Oxygen Master Regulator Mark X, British RAF, 106D/24, For Parts or Repair SN7836 WW1 both pointers are at the

both pointers are at the 0 degree position) that can be set at a target degree range by turning the knob

which will coincide with the compass reading once on course

a lens gasket

NOTE:  the second pointer is missing

Based upon the service label from Naval Air Station Norfolk (VA) dated 1954

Oxygen Master Regulator Mark X, British RAF, 106D/24, For Parts or Repair SN7836 WW1 both pointers are at theThis WWII era Oxygen Master Regulator Mark X was used in large bomber aircraft of the British Royal Air Force and Royal Canadian Air Force, such as the Avro Lancaster. The Mk X regulator was for a high pressure continuous flow oxygen system and allowed the pilot to control the flow of oxygen centrally for up to 8 crewmen. The left hand knob controlled the flow of oxygen, which would be displayed on the ALT gauge. The flow was to be set to match the