U.S. Army M9 Field Protective Gas Mask

The U.S. Army M9 Field Protective Gas Mask came after further development of the M5-11-7, which also used a 60mm M11 filter attached directly to the cheek.  This design saw many years of use, and was copied by several other countries.  Production began in 1951, but less than a year later the carrier was updated, and the designation was changed to M9A1.  This example's filter port is on the right cheek to accomodate left handed soldiers, and was made by Firestone in 1951.

Rubber stamp
Rubber stamp

Manufacturer and date stamps on cheek "M94C2" "51 (Firestone logo) E1"

Stamp
Stamp

Lot stamp on cheek "CH-11015-10000"

Rubber stamp
Rubber stamp

Size stamp on forehead "US M"

Rubber stamps
Rubber stamps

Date stamp on exhale valve "51 D E-1" "M20-C11"

Rubber stamp
Rubber stamp

Stamp inside mask "M11 C1"

Filter connector
Filter connector

60mm filter connector "UNITED CAPR"

Filter
Filter

FIlter top view

Filter
Filter

FIlter stamps bottom view "US MII" "L"

Filter
Filter

FIlter lot stamp side view "LOT EA-25131-31"