The Stir 18L Backpack is made of 210D Robic and 70D nylon, offering a durable and lightweight design. It features an 18-liter volume with dimensions of 7.9 x 17.7 x 8.3 inches. The backpack includes a breathable shoulder strap, a sternum strap, and a waist belt for support and suspension. It is hydration compatible but does not include a reservoir. Access is through the front panel, with one top and one side pocket, plus gear loops.