AirBoss CBRN C4 Gas Mask Size MEDIUM Left and right filter positions that accept all standard NATO canisters (i.e. C2A1, C7). Anti-fog lenses offer a wide field of vision and are made with fragmentation and shatterproof polycarbonate. Easy to use drinking system that adapts to the USM1 and Canadian canteen caps. Thanks to a perfectly fitted stretch fabric head harness with two simple adjustment pull straps, the C4 respirator is fast and easy to don and doff. This respirator also has an ergonomic butyl face piece designed to perfectly adapt to individual activities and requirements. Filter not included. Comes with versatile Carrier Bag