Constructed of heavy weight water-repellent 600 Denier pack cloth fabric, the Mil-Pack 45 Liter backpack is ideal for keeping your gear, supplies, and photo equipment secure and protected from the elements in rugged outdoor conditions and wet weather while providing exceptional storage and comfort in a lightweight under 3 pound design. Its padded back panel with built-in ventilation channels gives you all-day comfort against shocks while hiking plus allows free passage of air to keep you cool. The shoulder straps and padded hip belt are fully adjustable for a custom fit that keeps your load balanced and secure. The convenient overall size of this 45 liter backpack, measuring 26"T x 17"W x 9"D, provides generous storage capacity and convenient access for all of your gear and supplies, with a 21 1/2"T x 14"W x 8"D main compartment, two extra-long 12"T x 6"W x 2 1/2"D side pouches with double zipper pulls with storm protective zipper covers, a 2 1/2"T x 10 1/2"W x 7 1/2"D top zipper-access compartment, and even a zippered map compartment in the rear of the cover.