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.

Rubber stamp
Rubber stamp

Manufacturer and date stamp on chin of ND Mk IV Gas Mask "GR-S MK-IV MSA LOT (?) 7 45

Rubber stamp
Rubber stamp

Manufacturer and date stamp on flutter valve of ND Mk IV Gas Mask "LOT 3 1940 MSA"

Carrier
Carrier

Khaki bag for "USN U Gask Mask ND Mark IV"

Carrier
Carrier

Gray bag for "USN U Gask Mask ND Mark IV"

Carrier
Carrier

Brown bag for "USN U Gask Mask ND Mark IV"

Unissued ND Mk IV
Unissued ND Mk IV

With knitted lens protectors

Unissued ND Mk IV
Unissued ND Mk IV

With cardboard flutter valve protector

Unissued ND Mk IV
Unissued ND Mk IV

With sealed filter

Faceform tag
Faceform tag

Tag for Navy Diaphragm Mark IV Gas Mask faceform