The Tac-Com was a radio transmitter in varying forms similar to a walkie-talkie used by the COG. This allowed Gears to contact other teams and control as well as see mission objectives (EG:"Mine says teach the rook the golden rule"). Although more often than not in ear-piece form and activated to receive or send by the touch of finger, the comm unit could also be switched to receive or send only, flicked off straight away or left on for however long was needed. Different frequencies could be set for each individual team for more private conversations they did not wish others to overhear, this also applying to between Control and Command, as was evident when Control was taken offline while Marcus and Dom were inside New Hope.