500 Liter Oxygen Reservoir, sky blue, with 4 D-rings, one in each corner, with all accessories, which includes 1 5L Divilbiss concentrator, 1 newly designed bulkhead, 2 Twin Port EWOT face mask (S, M or L), comes with 25mm upper intake valves, 1 syringe for putting air in the face mask for ease of comfort, 2 harnesses, 1 tripod system for hanging, 12' 22mm high volume hose. 12ft comes in 2 6 foot sections with oversized connecting adapter, 8 feet of 1/4 inch silicone fill hose, and 1 oximeter.