Complete Avon FM53 M53 Gas Mask Air Purifying Respirator SEAL DEVGRU CAG Large. These mask are primarily used by United States Special Operation Units across all branches. These are SCBA capable. These accept all standard 40mm nato filters. This set comes with. NEW Carrying Bag Grey. NEW sealed 40mm filter. NEW Waterproof Storage bag. NEW Clear Outserts assembly. This set is a Large with Filter on the left side of the face. This item is ITAR Restricted.