Material: Arvano Cycle Backpack,made Of High Quality, Durable Ripstop Material & Best-quality Zippers. The Main Compartment Has A Double Zip And An Internal Elasticated Pocket.this Bicycle Backpack Has A Bladder Compartment, It Includes A Top Hole For Passing A Drinking Tube Through,for 1.5-2 Litre Water Bags. A Compartment Designed To Store Your Quick-dry Sweat Towel, Umbrella Or Wallet.lightweight And Comfortable: 18*8.6*1.5 Inches In Size And 1.1 Lb In Weight, With 6 L In Capacity. It Adds No Heavy Burden To Your Travel Load. Adjustable Shoulder, Chest And Waist Straps To Ensure A Stable And Suitable Carry For Perfect Fit,so The Pack Will Not Bounce While Cycling.it's A Perfect Biking Backpack Or Running Backpack.design For Biking: The Small Cycling Backpack Has Ergonomic Design On The Back Comfort. Integrated Breathable Sponge Mesh In The Back,breathable And Not Muggy. Reflective Strips For Safe Riding At Night. Arvano Hydration Packs Are Designed Specifically For Road Cycling/motor Bike/mountain Biking/other Outdoor Activities.headphone Output : On The Front Of This Riding Backpack,there Is A Small Compartment With A Zipper, Which Offers Space For A Cell Phone. The Output Can Also Used For Headphones.must Equipment For Outdoor Sports:lightweight Suitable For Outdoor Activities Like Outdoor . Running Camping Mountain Climbing, Hill Walking, Cycling, Rock-climbing And Hiking,skiing,mtb,motor Cycling, Dirt Bike,rave,music Festival,etc.for Men,women And Teens. Made Of High Quality, Durable Ripstop Material & Best-quality Zippers. Back Ventilation, Perfect, The Upholstery On The Back Very Comfortable Make Reflector Elements Calm And Safe While Cycling At Night