Features: 1Aviation aluminum: aviation aluminum, standard portable oxygen tank parameters, and meet the diving equipment manufacturing standards. 2Top release, press the top to release the pressure in the bottle. The pressure shall not exceed 20. 3Regulator: a single regulator that is open at all times and breathes as needed, with a pressure gauge indicating how much air is in it. 4Engineering silicone mouthpiece, safe and fits ergonomic design. 5Please refer to relevant video and instruction before use. Condition: 100% Brand New Item Type: Oxygen Cylinder Model: S300 Material: aviation aluminum silica gel Size: approx. 5.8x13x35.2x6cm/2.3x5.1x13.9x2.4inch Capacity: 0.5L Gas capacity: 3.0 CU FT / 85 LITERS Length: 13.4 / 34 cm Diameter: 2.25: LB. / 5.71 CM Maximum pressure: 3000 PSI/200 BAR/20MPA The surface of the water breathing: about 30 times (calculated on each breath 2.5 LITERS) (It can breathe about 57 breaths on the surface of the water, and adults can breathe about 21 times underwater for 7 meters and 6 minutes. The product contains an inflatable head, which can be directly inflated in a standard diving cylinder and can be fixed on BCD. This product is easy to carry and has an independent respiratory system) Package included:1 x Oxygen Cylinder Head1 x Oxygen Cylinder&nbsp2 x Rubber Ring1 x Hex Wrench1 x Manual