Mingus Hydration Pack Backpack 3L Water Bladder, Water Rucksack Drinking Bag for Cycling Bicycle Bike Hiking Travel Climbing and Other Outdoor Sports Constructed by waterproof durable 600D high density nylon material; Two layers cargo design, one for hydration bladder, and the other for extra carrying purpose; Capacity: 3L, Large filling port with secure seal; Bite valve design, convenient for switch on/off the flow of water; With hand carry strap and adjustable shoulder straps are suitable for convenient for hiking, climbing, riding and other outdoor sports.