U.S. NORBA Type A-3
The U.S. Navy Oxygen Rescue Breathing Apparatus Type A-3 used a facepiece very similar to the U.S. ND Mk IV made of black Hycar rubber. When connected to a rebreather system, it was suitable for use in smoke and other environments lacking sufficient oxygen. This example was made by Mine Safety Appliances in 1966.
Stamp on forehead "USN"
Manufacturer and date stamps under chin "65/66/67" "MSA" "HYCAR RUBBER"
Date stamp on hose "65/66/67"