What is a m40 made of?

The M40 is a type of military gas mask primarily made from a combination of rubber and various plastics to provide a flexible yet durable seal against chemical agents. It features a facepiece, a filter canister, and a harness system for secure fitting. The materials are designed to withstand harsh conditions while offering protection and comfort to the wearer. Additionally, the lens is made from polycarbonate to ensure visibility and impact resistance.