Marmot Graviton 38 Pack 70d 100% Nylon Robic Ripstop Material: [main] 70D nylon ripstop, [reinforcements] 100D nylon ripstop Volume: 40L (2440cu in) Support/Suspension: Ventilated Airflow Suspension, Tubular Aluminum Frame Shoulder Straps: airmesh Waist Belt: yes, padded