... air breathing apparatus,4 hours usage time Movable long-tube positive pressure air breathing apparatusPurposes of productMovable long-tube positive pressure air breathing apparatus ... generally consists of stainless steel body, 4 air cylinders, 2 high pressure connecting ducts, 2 exhaust valve, 2 ... direction valves, 1 reducer base, 1 reducer, 1 high pressure meter, 1 meduim connecting pipe, 1 quarter ...