Three Mile Island is considered the worst nuclear emergency to take place on U.S soil. In the aftermath of the accident, technicians were called upon to enter the Unit 2 Reactor Building, ground zero, in order to assess the damage caused by this horrific catastrophe. Because of the implications of the radioactive environment, the techs had to wear full-coverage protective clothing and gloves which called for specialized communication equipment. Each person was equipped with a Setcom GM-312 Face Mask Kit and a Setcom Portable radio cable assembly to interface the kit to a Motorola MX series radio worn on a belt. The Setcom Kit included a bone conduction microphone, a unique device designed to respond to voice vibrations transmitted through the skull. Since this microphone was not in the facial portion of the face mask, mask integrity was maintained. This specialized application made it possible for all communications to be recorded and studied to further the investigation into why there was an accident and how much damage it had caused.