Black Diamond Cosmo 350-R Headlamp, Octane
The Cosmo 350 is a simple and versatile light with night vision option, making it an ideal companion on camping trips, in the home and on all your outdoor adventures. If there is no power source available, for example on a long trekking tour, the lamp can also be operated with alkaline batteries. Dualfuel: Powered by three AAA alkaline batteries (included) or the rechargeable BD 1500 lithiumion battery and charger (sold separately) for maximum flexibility. Highest level with 350 lumens. Night vision mode (red LED) with dimming and flashing mode, is quickly activated via two buttons. Setting options include dimming mode, flashing mode, night vision mode (red) and a lock mode. Optical facetted lens IPX8: Waterproof and tested to operate up to 1.1 metres under water for 30 minutes. When submerged, water can enter the interior of the battery housing without affecting the function of the lamp. After operation in a wet environment, the lamp should be dried completely. Integrated battery power meter shows the remaining life in %. Digital lock mode prevents accidental switchon in the backpack or pocket.
The Cosmo 350 is a simple and versatile light with night vision option, making it an ideal companion on camping trips, in the home and on all your outdoor adventures. If there is no power source available, for example on a long trekking tour, the lamp can also be operated with alkaline batteries. Dualfuel: Powered by three AAA alkaline batteries (included) or the rechargeable BD 1500 lithiumion battery and charger (sold separately) for maximum flexibility. Highest level with 350 lumens. Night vision mode (red LED) with dimming and flashing mode, is quickly activated via two buttons. Setting options include dimming mode, flashing mode, night vision mode (red) and a lock mode. Optical facetted lens IPX8: Waterproof and tested to operate up to 1.1 metres under water for 30 minutes. When submerged, water can enter the interior of the battery housing without affecting the function of the lamp. After operation in a wet environment, the lamp should be dried completely. Integrated battery power meter shows the remaining life in %. Digital lock mode prevents accidental switchon in the backpack or pocket.
The Cosmo 350 is a simple and versatile light with night vision option, making it an ideal companion on camping trips, in the home and on all your outdoor adventures. If there is no power source available, for example on a long trekking tour, the lamp can also be operated with alkaline batteries. Dualfuel: Powered by three AAA alkaline batteries (included) or the rechargeable BD 1500 lithiumion battery and charger (sold separately) for maximum flexibility. Highest level with 350 lumens. Night vision mode (red LED) with dimming and flashing mode, is quickly activated via two buttons. Setting options include dimming mode, flashing mode, night vision mode (red) and a lock mode. Optical facetted lens IPX8: Waterproof and tested to operate up to 1.1 metres under water for 30 minutes. When submerged, water can enter the interior of the battery housing without affecting the function of the lamp. After operation in a wet environment, the lamp should be dried completely. Integrated battery power meter shows the remaining life in %. Digital lock mode prevents accidental switchon in the backpack or pocket.
The Cosmo 350 is a simple and versatile light with night vision option, making it an ideal companion on camping trips, in the home and on all your outdoor adventures. If there is no power source available, for example on a long trekking tour, the lamp can also be operated with alkaline batteries. Dualfuel: Powered by three AAA alkaline batteries (included) or the rechargeable BD 1500 lithiumion battery and charger (sold separately) for maximum flexibility. Highest level with 350 lumens. Night vision mode (red LED) with dimming and flashing mode, is quickly activated via two buttons. Setting options include dimming mode, flashing mode, night vision mode (red) and a lock mode. Optical facetted lens IPX8: Waterproof and tested to operate up to 1.1 metres under water for 30 minutes. When submerged, water can enter the interior of the battery housing without affecting the function of the lamp. After operation in a wet environment, the lamp should be dried completely. Integrated battery power meter shows the remaining life in %. Digital lock mode prevents accidental switchon in the backpack or pocket.
in 8 offers
The lowest price for Black Diamond Cosmo 350-R Headlamp, Octane right now is $48.28 at Telemark Pyrenees, compared across 8 retailers.
The all-time low was $48.28 on 19 Aug 2026. That's the lowest price we've ever tracked — a great time to buy.
Prices last updated 19 Aug 2026.
Last updated at 19/08/2026 13:19:53
BLACK DIAMOND Cosmo 350-R Rechargeable LED Headlamp, Waterproof and Dimmable Headlamp for Camping, Hiking, Running, with Red Light Headlamp Mode,
Affiliate Disclosure: We may receive a small commission for purchases made through this link at no extra cost to you. This helps support our site. Thank you!
Black Diamond Cosmo 350-R Headlamp
Delivery $26.55
BD Black Diamond Cosmo 350-R headlamp-Octane
Delivery by 27 Aug $37.95
Black Diamond Cosmo 350-r Headlamp Red 350 Lumens
Delivery $19.99
Black Diamond Cosmo 350-R lm Front Light Red
Black Diamond Cosmo 350-R Headlamp Octane
Delivery $7.99
Black Diamond Cosmo 350-R Rechargeable Headlamp Octane
Delivery $25.43
Black Diamond Cosmo 350-R Rechargeable Headlamp - Yuenye Warehouse Octane Orange
Free delivery
originally posted on REI
HeadlampI’ve used several different brands and models of headlamps over the years. I was provided this one to review. It arrived locked, but that was easy enough to disable following the directions provided. It had about 75% charge to begin with. I fully charged it and have been using it off and on for the past three weeks. I haven’t needed to re-charge it yet, so I’d judge the battery life to be pretty good. With a 3-year warranty you should be able to count on the product to last that long, but with a non-replaceable battery, it doesn’t make the best long term solution for me. I’m a BIFL kind of person and once I like something, I want to keep it for a long time and I’m willing to maintain things. If you like to update as new products are released, this would ... MoreHeadlampI’ve used several different brands and models of headlamps over the years. I was provided this one to review. It arrived locked, but that was easy enough to disable following the directions provided. It had about 75% charge to begin with. I fully charged it and have been using it off and on for the past three weeks. I haven’t needed to re-charge it yet, so I’d judge the battery life to be pretty good. With a 3-year warranty you should be able to count on the product to last that long, but with a non-replaceable battery, it doesn’t make the best long term solution for me. I’m a BIFL kind of person and once I like something, I want to keep it for a long time and I’m willing to maintain things. If you like to update as new products are released, this would feels like a durable product that would last until you’re ready for the next new one.It’s a minimalist product with a flat profile all the way around. The buckles stay even as the strap sides adjust simultaneously. The strap feels abrasive on my forehead, but it would be easy enough to put something around the part of the strap touching there, or to use an entirely different strap. The headlamp has cutouts that allow changing straps or attach it to a chest strap on a backpack which I think is a cool feature.The provided cable is of average quality and short, 4” total length. Short works for me as it’s lightweight and easier to pack, although it is disappointing that the cable is USB-A to micro USB. At the least, the headlamp should have USB-C instead of the outdated micro USB. There’s no charging block, but that’s not uncommon.The box had conflicting water resistance ratings (IP67 on the box, IPX8 in the instructions), but I emailed Black Diamond customer service and they were quick to reply (IP67 is correct) and they let me know they’d forwarded the information to the design team to correct the discrepancy.
originally posted on REI
Bought this to replace my trusty Petzl after one of the NiCad batteries suddenly leaked and ruined the plastic case. Quite the unpleasant surprise, because I check my headlamp before every hike, even if only a day hike, and it had only been a couple of weeks since the last hike.Pros: Black Diamond has a good reputation for quality products and this headlamp appears to live up to that standard. Time will tell, but very happy so far. Simple and intuitive controls. Good features for the price.Cons: None found so far.Bottom line. I'm almost glad to have been pushed into a rechargeable device. Wondering how much life was left in the NiCads and always carrying spares was one more hassle. Put this one on the charger before each trip and you are good to go.
originally posted on REI
There is a lot to like about the Black Diamond Cosmo 350 headlamp. It is an excellent headlamp that is very versatile and an excellent performer. It has LED white and red beams with a button for switching light modes with ease. I like that it has a red beam I rely on when in a multi-person tent or a trail shelter. It includes dimming and strobe functions with a broad range of light brightness for all situations. Given that I dislike constantly changing expended batteries and packing extras, I particularly like its rechargeable battery with the option of switching to AAA batteries. If you have ever drained your lamp batteries by mistakenly turning the lamp on when packing, you will appreciate the digital lockout function it includes. Finally, the lamp is waterproof ... MoreThere is a lot to like about the Black Diamond Cosmo 350 headlamp. It is an excellent headlamp that is very versatile and an excellent performer. It has LED white and red beams with a button for switching light modes with ease. I like that it has a red beam I rely on when in a multi-person tent or a trail shelter. It includes dimming and strobe functions with a broad range of light brightness for all situations. Given that I dislike constantly changing expended batteries and packing extras, I particularly like its rechargeable battery with the option of switching to AAA batteries. If you have ever drained your lamp batteries by mistakenly turning the lamp on when packing, you will appreciate the digital lockout function it includes. Finally, the lamp is waterproof which makes it reliable when in rainy conditions. I’ve owned and used many headlamps from an array of makers and this is the best headlamp I’ve owned. I recommend it if you are seeking a versatile, good-performing headlamp you can use for many activities.
| Maximum Lamp Distance | 65 m |
| Maximum Lamp Power | 350 lm |
| Red light | Front |
| Energy | Rechargeable batterie |
| Batterie incluse | Yes |
BLACK DIAMOND Cosmo 350-R Rechargeable LED Headlamp, Waterproof and Dimmable Headlamp for Camping, Hiking, Running, with Red Light Headlamp Mode,
Affiliate Disclosure: We may receive a small commission for purchases made through this link at no extra cost to you. This helps support our site. Thank you!
Black Diamond Cosmo 350-R Headlamp
Delivery $26.55
BD Black Diamond Cosmo 350-R headlamp-Octane
Delivery by 27 Aug $37.95
Black Diamond Cosmo 350-r Headlamp Red 350 Lumens
Delivery $19.99
Black Diamond Cosmo 350-R lm Front Light Red
HeadlampI’ve used several different brands and models of headlamps over the years. I was provided this one to review. It arrived locked, but that was easy enough to disable following the directions provided. It had about 75% charge to begin with. I fully charged it and have been using it off and on for the past three weeks. I haven’t needed to re-charge it yet, so I’d judge the battery life to be pretty good. With a 3-year warranty you should be able to count on the product to last that long, but with a non-replaceable battery, it doesn’t make the best long term solution for me. I’m a BIFL kind of person and once I like something, I want to keep it for a long time and I’m willing to maintain things. If you like to update as new products are released, this would ... MoreHeadlampI’ve used several different brands and models of headlamps over the years. I was provided this one to review. It arrived locked, but that was easy enough to disable following the directions provided. It had about 75% charge to begin with. I fully charged it and have been using it off and on for the past three weeks. I haven’t needed to re-charge it yet, so I’d judge the battery life to be pretty good. With a 3-year warranty you should be able to count on the product to last that long, but with a non-replaceable battery, it doesn’t make the best long term solution for me. I’m a BIFL kind of person and once I like something, I want to keep it for a long time and I’m willing to maintain things. If you like to update as new products are released, this would feels like a durable product that would last until you’re ready for the next new one.It’s a minimalist product with a flat profile all the way around. The buckles stay even as the strap sides adjust simultaneously. The strap feels abrasive on my forehead, but it would be easy enough to put something around the part of the strap touching there, or to use an entirely different strap. The headlamp has cutouts that allow changing straps or attach it to a chest strap on a backpack which I think is a cool feature.The provided cable is of average quality and short, 4” total length. Short works for me as it’s lightweight and easier to pack, although it is disappointing that the cable is USB-A to micro USB. At the least, the headlamp should have USB-C instead of the outdated micro USB. There’s no charging block, but that’s not uncommon.The box had conflicting water resistance ratings (IP67 on the box, IPX8 in the instructions), but I emailed Black Diamond customer service and they were quick to reply (IP67 is correct) and they let me know they’d forwarded the information to the design team to correct the discrepancy.
Bought this to replace my trusty Petzl after one of the NiCad batteries suddenly leaked and ruined the plastic case. Quite the unpleasant surprise, because I check my headlamp before every hike, even if only a day hike, and it had only been a couple of weeks since the last hike.Pros: Black Diamond has a good reputation for quality products and this headlamp appears to live up to that standard. Time will tell, but very happy so far. Simple and intuitive controls. Good features for the price.Cons: None found so far.Bottom line. I'm almost glad to have been pushed into a rechargeable device. Wondering how much life was left in the NiCads and always carrying spares was one more hassle. Put this one on the charger before each trip and you are good to go.
There is a lot to like about the Black Diamond Cosmo 350 headlamp. It is an excellent headlamp that is very versatile and an excellent performer. It has LED white and red beams with a button for switching light modes with ease. I like that it has a red beam I rely on when in a multi-person tent or a trail shelter. It includes dimming and strobe functions with a broad range of light brightness for all situations. Given that I dislike constantly changing expended batteries and packing extras, I particularly like its rechargeable battery with the option of switching to AAA batteries. If you have ever drained your lamp batteries by mistakenly turning the lamp on when packing, you will appreciate the digital lockout function it includes. Finally, the lamp is waterproof ... MoreThere is a lot to like about the Black Diamond Cosmo 350 headlamp. It is an excellent headlamp that is very versatile and an excellent performer. It has LED white and red beams with a button for switching light modes with ease. I like that it has a red beam I rely on when in a multi-person tent or a trail shelter. It includes dimming and strobe functions with a broad range of light brightness for all situations. Given that I dislike constantly changing expended batteries and packing extras, I particularly like its rechargeable battery with the option of switching to AAA batteries. If you have ever drained your lamp batteries by mistakenly turning the lamp on when packing, you will appreciate the digital lockout function it includes. Finally, the lamp is waterproof which makes it reliable when in rainy conditions. I’ve owned and used many headlamps from an array of makers and this is the best headlamp I’ve owned. I recommend it if you are seeking a versatile, good-performing headlamp you can use for many activities.
I purchased the red version of this earlier this year and really liked the product so I purchased a second for my partner. I took both camping this past weekend to Summer Lake to watch the eclipse with my toddler. While I was in the tent changing my toddler's shirt the first night, I set this on my Big Agnes King Solomon down sleeping bag for maybe 30 seconds until I started smelling a burning smell. I grabbed the headlamp and it had burned a hole in my sleeping bag because it had gotten so hot in that time.This is a fire hazard. I could have started a fire in my tent with a toddler because of this headlamp being defective. The other headlamp I purchased does not heat up in the same way. Check your headlamps before use to make sure they do not heat up as they could ... MoreI purchased the red version of this earlier this year and really liked the product so I purchased a second for my partner. I took both camping this past weekend to Summer Lake to watch the eclipse with my toddler. While I was in the tent changing my toddler's shirt the first night, I set this on my Big Agnes King Solomon down sleeping bag for maybe 30 seconds until I started smelling a burning smell. I grabbed the headlamp and it had burned a hole in my sleeping bag because it had gotten so hot in that time.This is a fire hazard. I could have started a fire in my tent with a toddler because of this headlamp being defective. The other headlamp I purchased does not heat up in the same way. Check your headlamps before use to make sure they do not heat up as they could cause serious damage.
My previous headlamp required batteries. Every trip, I wondered whether I had enough juice left - or did I need to carry extra batteries.So it's delightful to switch to a headlamp like the Black Diamond ("Cosmo 350-4") because it's rechargeable. (And the recharging cable is the same as the one for my other backpacking electronics so... only one cord to carry!)The headlamp is lightweight and easy to angle. The headstrap is like other headlamps I’ve used: I had to keep readjusting it. But me and headlamp-style buckles never seem to work together; I may try a different strap at some point.As well as a strong white light, the Black Diamond offers red light - the one I nearly always use to avoid killing my night vision.The intensity of both the white light and ... MoreMy previous headlamp required batteries. Every trip, I wondered whether I had enough juice left - or did I need to carry extra batteries.So it's delightful to switch to a headlamp like the Black Diamond ("Cosmo 350-4") because it's rechargeable. (And the recharging cable is the same as the one for my other backpacking electronics so... only one cord to carry!)The headlamp is lightweight and easy to angle. The headstrap is like other headlamps I’ve used: I had to keep readjusting it. But me and headlamp-style buckles never seem to work together; I may try a different strap at some point.As well as a strong white light, the Black Diamond offers red light - the one I nearly always use to avoid killing my night vision.The intensity of both the white light and the red light can be easily adjusted, by holding down one of the two buttons. And each is also available as a strobe.One thing to know: When you turn the light off, the tiny blue lights that show the power level light up for a few seconds. So, I'd expect total darkness but get that blue glow for a few seconds first.I haven’t compared the top brightness of this headlamp with others. But it got as bright as I needed it to be, in both white light and red light. And I liked being able to dim either shade.The headlamp worked equally well in a heavy, cold Welsh rain as in a steamy hot North Carolina summer night.And… did you know that fireflies really like red light? As soon as I turned my headlamp on, I had lots of new blinking friends. When my colleagues turned on their white headlamps, the fireflies couldn’t care less.I found an extra use for the headlamp while staying at a friend's house after camping: It makes a great nightlight! I was unfamiliar with the room I was in, so it was nice to set the headlamp on the dresser and leave it on the lowest setting of white light.The Cosmo headlamp will be part of my gear for hiking, camping - and any other stays away from home.
The Black Diamond Cosmo 350-R Headlamp is one of several headlamps I've had over the years. Previous headlamps were all of the replaceable battery styles, and had predictably average battery lifetimes. The rechargeable LiOn battery in the Cosmo headlamp is far longer in all modes, and charges rapidly with a USB-C cable. At the lowest setting the lamp will function for 9 days, i.e., 9x24 hours. At this level of lighting one can easily read a book or have a useful night light in a hotel bathroom for the duration of a typical vacation. At full brightness one can easily see where they are hiking on dark forest trails at night, or even when riding a bike at moderate speed. The adjustable band is fairly comfortable, though when appropriately tight marks are made against ... MoreThe Black Diamond Cosmo 350-R Headlamp is one of several headlamps I've had over the years. Previous headlamps were all of the replaceable battery styles, and had predictably average battery lifetimes. The rechargeable LiOn battery in the Cosmo headlamp is far longer in all modes, and charges rapidly with a USB-C cable. At the lowest setting the lamp will function for 9 days, i.e., 9x24 hours. At this level of lighting one can easily read a book or have a useful night light in a hotel bathroom for the duration of a typical vacation. At full brightness one can easily see where they are hiking on dark forest trails at night, or even when riding a bike at moderate speed. The adjustable band is fairly comfortable, though when appropriately tight marks are made against one's forehead. There is a tilt adjustment available to direct the light as needed. I did not test the waterproof features, but the seals for the switches and USB connector appear to be adequate for shallow water immersion. The level of charge remaining is displayed by three tiny blue LEDs that illuminate when the light is turned off. I'd also recommend this for paddling excursions. The only negative issue encountered - and this will happen with any headlamp - is that insects are attracted to light and therefore your face.
I used this product camping and evening hiking so far. It is good to see more rechargable headlamps entering the market. I was impressed with the features of this headlamp which seem to be durable and quality. My headlamp comes with a red light separate from the main light. This lamp has a unique way of adjusting the brightness which is to hold down the button rather than click through them. Then to click briefly to turn it on and off. Best of all, memory brightness so you don't have to start from the beginning every time. I think this all means that the buttons will last longer. It did take me a few times practicing to use the buttons effectively, but now I like it a lot more.The brightness of the red light was just about right for reading or to move around at ... MoreI used this product camping and evening hiking so far. It is good to see more rechargable headlamps entering the market. I was impressed with the features of this headlamp which seem to be durable and quality. My headlamp comes with a red light separate from the main light. This lamp has a unique way of adjusting the brightness which is to hold down the button rather than click through them. Then to click briefly to turn it on and off. Best of all, memory brightness so you don't have to start from the beginning every time. I think this all means that the buttons will last longer. It did take me a few times practicing to use the buttons effectively, but now I like it a lot more.The brightness of the red light was just about right for reading or to move around at night without disturbing others nearby. I appreciate the clarity of the main light the most which seems to deliver to a higher level than I've seen in other products. This headlamp also tilts down nicely and can strap to your waist. My friends reported that this worked well and didn't blind them when I looked at them.I plan to take this backpacking on the JMT this summer. According to the manual, a medium setting will last 10 hours and low for 225 hours. This weighs 75g but I think I can cut back on half of that by using a shock cord instead of the bulky head strap.
I wanted a light that you plug in to charge with an integrated recharging battery. I didn't want to use rechargeable batteries or need a special battery or charger. This is PERFECT. It came with the charging cable and you just need the USB part that goes into the wall. I've used this headlamp on my last three camping trips. It charged up great and the light is really bright (my camping buddies say it's a bit too bright when we're just hanging out at home base). I haven't had to recharge it yet. I'm still learning the modes, and all in all I'm very happy! It is light weight, fits and adjusts well and the light tilts like other good headlamps.
I was not able to use this in the wilderness because it got wet on my way to a campsite and stopped working. The packaging states it is submersible, IPX7, so it can be submersed up to a meter, for 30 min. I had an unfortunate accident where my gear was floating in about 6 inches of water for 10 minutes. My headlamp stopped working after that, water got behind the lens, and it wouldn't hold a charge. Fully charged (3 battery LED's) before the accident - one battery LED after the accident. It would turn on, but only had about 30 min of "on-time" left. Had to cut a trip short because of this. If you plan on being in or around water with this headlamp, test it out before you get into the wilderness!
This headlamp works wonderfully. I found that it was incredibly lightweight, and the band supplied was comfortable. I also like that it is rechargeable and that the headlamp can be separated from the band and placed somewhere else maybe for storage, or strapped onto something else like a chest strap of a backpack. The lighting modes were intuitive and I really enjoyed the dynamic dimming modes, which felt easier to use than other headlamps I have used before. I think that this headlamp could potentially run in to issues if it was tested in an extremely cold environment for multiple days at a time, but for the typical 1-3 day backpacking trip this would be a wonderful choice. The red light mode was useful in very dark conditions, and I was pleasantly surprised to ... MoreThis headlamp works wonderfully. I found that it was incredibly lightweight, and the band supplied was comfortable. I also like that it is rechargeable and that the headlamp can be separated from the band and placed somewhere else maybe for storage, or strapped onto something else like a chest strap of a backpack. The lighting modes were intuitive and I really enjoyed the dynamic dimming modes, which felt easier to use than other headlamps I have used before. I think that this headlamp could potentially run in to issues if it was tested in an extremely cold environment for multiple days at a time, but for the typical 1-3 day backpacking trip this would be a wonderful choice. The red light mode was useful in very dark conditions, and I was pleasantly surprised to find that the red light was also dimmable. I tested the headlamp multiple times indoors and outdoors in varying light levels including a "simulated" pitch black room in my house, which let me really test the red light mode and dim levels of the regular lamp mode. I found that reading text with the red light and regular lamp mode was quite easy, which could be beneficial in some odd situation that you needed to read something while backpacking (i.e. a medical emergency). I'm not quite sure how someone would recharge this headlamp on an extended backpacking trip, which is why I said that its best for a 1-3 day adventure, but I'm sure with good battery management someone could make this headlamp work for a week long trip.
| Maximum Lamp Distance | 65 m |
| Maximum Lamp Power | 350 lm |
| Red light | Front |
| Energy | Rechargeable batterie |
| Batterie incluse | Yes |
