USGI M44 Chemical-Biological Gas Mask Filter Canister 4240-01-361-1319 New USA

It is threaded in 40mm (specifically; It uses the Rd40 x 1/7″ thread (NATO Standard), making it compatible with most gas masks, particularly all current NATO gas masks. The modern production C2a1 filters are sealed in a plastic container to keep the filter components fresh and unexpired. The latest run of C2a1 gas mask filters are marked (ASZM-TEDA), C2a1. The (ASZM-TEDA) signifies that these canisters are manufactured with a new type of Impregnated Carbon which offers increased protection against Chemical agents. It still does not offer full protection against Ammonia-based weapons or Ammonia fumes. It probably offers some protection against these, but is not enough to protect the user against Ammonia-based agents or Ammonia fumes

The C2A1 DIN Threaded Canister is Intended to Reduce Exposure to Chemical and Biological Warfare Agents and is used by the United States Military.

• C2A1 Canister Protects the User From Up To 15 Nerve, Choking, Blister Agent Attacks, and Two Blood Agent Attacks.