Black Diamond Speed Zip 33 Backpack Polyester Material: 210D ripstop nylon, 420D nylon Volume: [small/medium] 31L (1892cu in), [medium/large] 33L (2014cu in) Support/Suspension: thermoformed back panel, framesheet (removable), foam bivy pad (removable) Shoulder Straps: ergonomic Waist Belt: yes, removable hipbelt (fixed webbing belt remains)