ALPS Mountaineering Arvada Daypack, Blue. Blue, lightweight polyester ripstop; Hydration pocket and port. Includes three liter bladder with insulated tube. Front stretch neoprene pockets; Side neoprene water bottle pocket. Padded back with air flow channel; Rescue whistle buckle on sternum strap. Capacity: 1220 cubic Inch/20L; Weight: 1 pound, 11 ounces; SKU 6011102.