PTT 401 - Click for TECH DRAWING - is small, low profile, low cost lower cordset with ring-type press to talk button - Plug and screw the headset securely into the junction box and the plug into your radio. Run the cable down your arm and Velcro the switch on a finger. The recessed switch button - assembly is positioned on the underside of a finger and held in place with a velcro strap so that the switch would be depressed by your thumb.