This is definitely a cheap knockoff of the SanDisk Extreme Pro SD cards. The labeling is intended to match the real item, and it looks pretty good, but you can clearly see the difference when comparing the packaging and SD card itself next to each other.Maximum read/write speeds have been tested at 20mbs/20mbs and the card works, but is very slow compared to the real Extreme Pro cards. These also have a tendency to disconnect during a large transfer and will only come back online once they are unplugged and plugged back in. If you are looking for cheap storage, these work, but if you need actual performance, stay away.

Best Micro SD Cards in the business.

SanDisk manufacture a great lineup of SSD, SD, and Micro SD Cards in the business. The Extreme Pro selection are the most responsive cards for our fast moving devices with those needs in film or photography work. A very reliable Card with the authentic Cards being of China, and those poorly performing fakes coming out of Taiwan. Be sure and select carefully by looking for the all important nomenclature etched on the backside of them.

Careful, double check them. Possible Counterfeits

Be careful with these. I had to return the two cards I got. I believe them to have been counterfeits. My GoPro Hero 7 Black would not even read them and in the laptop they failed the speed test horribly. From what I have found online those are good indicators that they are not authentic.

Counterfeit fake.

Looks real. Speeds are only 15Mbs no where close to 90 or 170. Also the Packaging said it was an Extreme Pro but the card says its just the Extreme. Different colored card than the Extreme Pro. So many red flags on this. You can tell by the packaging from the image that this is a fake. Also doesn't come with RescuePRO that the real ones come with. I'll be returning both of these. Buyer beware. I will say it does work for the most part but I need the advertised speed.

Disappointing Performance

Very slow write speed. Received read / write errors. Suspected counterfeit; not an actual SanDisk microSD card. Replaced with a smaller capacity--known good--SanDisk microSD card and the performance improved immensely.

Epic card

This SanDisk Extreme Pro is a marvelous card and has never let me down. It is used primarily for 4K at 30 frames per second. For continuous drone work and tripod bird photography the footage is superb with no lag. The upload and download speeds are exactly what this type of card should produce.

Genuine top quality 4k UHD micro sd card

This was the cheapest 256gb micro sd card I could find, and was concerned that it may be a cheap copy / fake. But it's not! I use mine to record 4k cctv images and when I first installed the card and formatted it, my cctv base unit confirmed the amount of free space was as stated. It also came with an adapter, which is useful, not not needed for my purposes. Very pleased indeed. I should say that that sd card specification is also the quickest I've encountered and ideal for 4k images.

Good build quality and decent speed

I bought the memory card to extend my laptop's storage without having to bother dismantling if. These micro cards are designed for digital devices, nevertheless I am satisfied and I can confirm they work well as a secondary or backup storage media. Read access is fast, far better than mechanical disks. Copying is slow, around 20mbits. The speed increases when writing directly to the SD, e.g. downloading from the internet. Pretty much the actual speed is limited by the controller and Operating System. I got the 256GB version, which for my pocket seems overpriced.

Great card for GoPro captures

SanDisk is my go to for CF, SD and Micro SD cards. I've never had a problem with them. Purchased the 256GB card to go in my GoPro Hero 10. Haven't had any issues. Created several multi-hour (~16, ~12, ~6 and ~4) TimeWarp movies on a recent fishing trip up to Northwest Ontario Canada from Northern Virginia and the card worked without issue. The GoPro overheated towards the end of the 16 hour capture, but that wasn't the cards fault. Actually as hot as GoPro's get I'm that much more impressed I didn't have any issues. Captured video anywhere from 1080(60fps) to 4K(30fps - might have been some 60 fps don't recall).

Nice addition to my Kindle Fire HD 10

Ordered to upgrade my Kindle Fire HD 10: when it finally arrived (delayed shipment) opened package, inserted in device and after a minute or two, my Kindle advised new downloads would now be stored on the MicroSD; zero tech problems. Took care of a lot of buffering problems I was experiencing. Good investment; makes my Kindle worth using.