Sports Hydration Backpack With Bladder Cycling Hydration Pack HP818 Material:nylon,Weight:14.1 oz,Dimensions:17.7x12.2x7.1inches 2L Bladder included,Thick mesh pads allow air flow to back Aircomfort vario-futura and wide straps,High air permeability Two side pockets big enough for wallet,phone,keys and other accessories Over 700 cubic inch capacity for full-day or overnight trips