The Kata 3N1-20 is a well-made bag with adjustable straps that can be set-up as a backpack or shoulder sling. The main compartment has a multi-access system that can quickly let you into the left side, the right side, or the whole thing. Theres a second compartment for personal items and a couple of exterior pockets, too. Inexcellent condition. Interior dimensions of gear compartment are approximately 15x20x30cm.