by Diesel Electronics
Requires a DC power source. You can install a 9V battery by removing the 2 screws on each side or plug a 9-13.8 DC volt power souce into the jack on the left side of the tester. Battery and DC power souce not included.
Test microphones and speakers for
Red LED Transmit light, Green LED Receive light, Volume switch, External speaker jacks
Instructions included
One year manufacturer warranty