Control Wheel Automatic Continuous Flow Oxygen Regulator with Oxygen Cylinder Pressure Indicator. It is the center section of the control wheel that houses the Oxygen Regulator on the back side of it and the indicator on the front of it. Unsure of type of aircraft it fits. Very clean item. It was removed from a salvage aircraft. Oxygen supply line end broke at the regulator receptacle end and will have to be removed if the regulator was to be used on an aircraft. Sold as is, no returns.