Motorola MTH800 and Motorola MTP850 radio earpieces for emergency service communications. The single pin connector with a secure screw works with most types of Motorola MTP and MTH radio. Here are the connector types that use this connection type MTH500, MTH650, MTH850, MTH800 MTP850.
Super Covert MP3 style, stay covert and inconspicuous whilst in full contact with others. You can look like you're listening to music, but with an in-line PTT and mic you can have full use of the 2 way radio.