The Canadian Large Field Pack/Framed 1982 pattern is constructed of Cordura Nylon that withstands a lot of abuse. The top of the pack is accessible via a zippered closure on top for easy access to the main bag. The main bag is 2200 cu.in with a map-pocket for smaller items. The side pockets are roomy and allow a pair of skis to be mounted underneath them. With a large main compartment, top-loading and three very usable (Large) accessories exterior pouches and a top compartment, you don't have to leave anything behind. The frame is incredibly lightweight with fully padded shoulder straps, lumbar pads, and fastex hardware . Large enough for cold weather treks, when the gear is voluminous and lightweight enough for the summer, this pack is such a great deal. The pack can be downsized easily to use it as a smaller pack, with its built-in compression straps. * Over 3000 cubic inches of storage.