ALPS Mountaineering Solitude Daypack, Rust Rust, lightweight polyester ripstop; Adjustable shoulder straps; Center aluminum frame stay Padded back with PE sheet; #10 main opening zipper; Large zippered front pocket Removable padded waist belt; Hydration pocket and port; Lower side neoprene pockets Dual side compression straps; Rescue whistle buckle on sternum strap Capacity: 2450 cubic Inch/40L; Weight: 3 pounds, 5 ounces; SKU 6643005