Head Set with Adjustable Boom Microphone . Simple to Install. Prewired for Standard 4 Pin Hookups: Cobra, Uniden, Galaxy, Newer Midland, Most all 10 Meter Radios Using 4 Pin Microphones Jacks. Microphone Type: Dynamic PTT Switch Mounted with Velcro Frequency Response: 100-10Khz Impedance: 500 Ohms Sensitivity: -80dB @1Khz Connect the cord that has a 2 pin male connector from the headset to the top of the Push to Talk box.  The other wire that comes out from the microphone plug is plugged into the external speaker jack at the back of the radio. Adjust the boom microphone for the best transmit quality.