Propulsion Harness™ moves in harmony with your shoulder and upper-back movements, reducing wasted energy Wall Mesh™ shoulder straps and back panel channel air across your skin and wick moisture away to improve overall comfort Rear main compartment stores a jacket or 1.5L hydration reservoir (not included) 4 front pockets include 1 zippered pocket, 1 pocket with drawcord closure; 1 waterproof pocket with rip-and-stick flap closure and 1 drop-in pocket