U.S. Navy Diaphragm Mk IV Gas Mask
The U.S. Navy Diaphragm Mk IV Gas Mask was an updated version of the U.S. ND Mk III, but with even larger triangular eyepieces. The filter clipped to the head harness behind the user's head, with two hoses drawing air up towards the eyepieces. This example was made by Mine Safety Appliances in 1945.
Manufacturer and date stamp on chin of ND Mk IV Gas Mask "GR-S MK-IV MSA LOT (?) 7 45
Manufacturer and date stamp on flutter valve of ND Mk IV Gas Mask "LOT 3 1940 MSA"
Khaki bag for "USN U Gask Mask ND Mark IV"
Gray bag for "USN U Gask Mask ND Mark IV"
Brown bag for "USN U Gask Mask ND Mark IV"
With knitted lens protectors
With cardboard flutter valve protector
With sealed filter
Tag for Navy Diaphragm Mark IV Gas Mask faceform