Material: 100D Robic HT nylon, 210D Robic HT nylon Volume: 35L (2135cu in) Support/Suspension: Perimeter Suspension (spring steel rod outline, PE sheet core) Shoulder Straps: dual-density Waist Belt: Re-Fit We all belong in the outdoors, and we love the Perimeter 35L Backpack's adjustable design that fits many body types. The suspension system is fine-tuned to the backpacker's body with two shoulder widths and multiple torso length options. This pack is excellent for both day hikes and multi-day trips, thanks to its side and top compression straps and roll-top closure.