H.E.L.M.

Hero Engaged Live Models or H.E.L.M's, are unique pieces of equipment that are able to be used by our heroes.  These helments give the ability to breathe in locations where oxygen is absent, or in areas where toxic gases or elements are present. They come in all shapes and sizes in order to meet the preferences of each party member.  
These devices also have a direct communications link to Tona-500, so he can be in continuous communication with the party.  The H.E.L.M.'s also show the player a HUD that lists their party memebers along with their corresponding vital signs.  The HUD also includes map layouts, mission specifics, and other useful information Tona may want to send the party's way.  
These H.E.L.M.s do not offer an AC, and do not need to be worn all the time.  Our players must be cautious however, as they may find themselves in a situation where oxygen has been removed from the room, or toxic elements are filling it.  If a player does not have on a H.E.L.M they will need to use a bonus action to put it on, or will be subject to tick damage that will drop their HP more and more each turn.