Extra Big Camouflage Backpacks (TB296C). Extra large school backpack or hiking backpack. This school backpack is constructed of 600 denier polyester, it has padded shoulder straps, large capacity multiple front pockets, large main compartment, metal key ring and safety buckles. The dimensions of this school backpack are 18 inches x 12 inches x 9.5 inches and 2,100 cubic inches.