U.S. Army M17-A1 Gas Mask

The US Army M17-A1 gas mask is a protective mask standardized in 1966 and widely used during the Vietnam War. It is the direct successor to the original 1959 ABC-M17 mask.

Key Features and Design

• Internal Cheek Filters: Unlike traditional masks, the M17 series does not use external filter canisters. The M13 filter elements ("pork chops") are tucked away inside the cheeks of the rubber mask itself. 
• Built-in Drinking System: The biggest upgrade of the A1 variant compared to the original M17 is the integrated drinking system. This allowed a soldier to drink water from a compatible canteen (M1 canteen) via a built-in tube without removing the mask. 
• Resuscitation System: The A1 featured a built-in resuscitation tube to breathe for an unconscious casualty. In practice, this proved dangerous due to the risk of cross-contamination and was quickly removed in the later M17A2 variant. 
• Speech Diaphragm: Equipped with a front-facing voicemitter to keep verbal communication intelligible.