These protective masks have inbuilt systems that facilitate communication, a tube for drinking water (A1 & A2), and a pair of outserts to protect eye lenses and prevent fogging. The mask is packed in a carrier that also contains other items like a nerve agent antidote kit (NAAK) and a convulsive antidote for nerve agents (CANA). It also contains a waterproof bag to protect filter elements from water damage. Other components attached are mask hoods to protect the head and neck area, a winterization kit to prevent frost accumulation during cold weather conditions and optical inserts for soldiers with vision defects. The A1 had a mask to mask resuscitation feature that was found to expose personnel to chemical agents. This forced the services to withdraw it from issue and replace it with the