The M9 Field Protective Mask is one of the most successful gas masks ever used by the United States military, with adaptations being adopted by at least six other countries. Originally produced just after WW2 around 1947, the M9 Series remained in standard infantry service until the early 1960s, proving its reliability and effectiveness in protecting against chemical, biological, and radiological threats. Even after being phased out from regular military use, the M9 series continued to serve the National Guardsmen and Law Enforcement, demonstrating its enduring value and durability. This classic piece of military surplus is a must-have for collectors and history enthusiasts.