Waterbag, Nylon Duck. Waterbag features double bar buckle shoulder straps to enable carrying drinking water on your back. It also includes a flap with a Velcro fastener and a replaceable plastic liner with a snap off rubber spigot. Made of nylon duck with foam insulation. 4 quart size. Government Issue. Brand New. Excellent quality. Would be great for hiking, riding, etc. We have the replacement plastic liners available also.