Lightweight, druable 210D nylon fabric. Insulated mesh back panel and ventilated mesh shoulder straps. 1 liter capacity bladder. By federal law, licensing fees paid to the U.S. Army for the use of its trademarks provide support to the Army Trademark Licensing Program, and net licensing revenue is devoted to U.S. Army Morale, Welfare, and Recreation programs. For more information, visit www.armymwr.com.Mini Hydration Pack with insulated mesh back panel and ventilated mesh shoulder straps is made of lightweight, durable 210 Denier nylon fabric. Features include a 1 liter capacity bladder and a front flap pocket. 7W x 12.75H x 2D. Great size for any activity.