Made of high quality, high density nylon fabric, waterproof, abrasion resistant and tear resistant. The front and rear reflective strips are designed to reflect strong light to keep you safe while riding or running at night. Hydration backpack includes a 2 Liter/70oz BPA free water bladder which keeps you hydrated. For maximum comfort, the back is padded with breathable mesh material from the cushions to the shoulder straps to help wick away sweat and breathe while riding or running. Cycling Hydration Pack: Cycling backpacks are perfect for those short bikers, runners and other sports enthusiasts. The space provides enough water storage for your exercise. Comes with a waist belt to stay on your body even with strenuous exercise. So help you release your burden or stress.