Alps Mountaineering Solitude Plus Backpack Two zippered side pockets; Blue, lightweight polyester ripstop; Adjustable shoulder straps Center aluminum frame stay; #10 main opening zipper; Padded back with PE sheet Large zippered front pocket; Removable padded waist belt Hydration pocket and port; Lower side neoprene pockets; Rescue whistle buckle on sternum strap Capacity: 3100 cubic Inch/50L; Weight: 3 pounds, 12 ounces; SKU 6746002