Doom Stunt RRTS Communicator Device

These little communicator devices were seen used in the movie Doom, most noticeably when Portman calls for back-up while hiding in the toilet cubicles and again later when Reaper gives one to his sister when she is left alone in the lab.
Stunt rubber versions like this one were clipped to the belts of Sarge and all of his team of RRTS soldiers throughout the movie.

Doom Comm 1