The Sigtronics Headset Tester will accommodate two headsets and includes a built-in Push-To-Test switch.
With this unit you may test one headset alone or two headsets together. Simply plug one or two headsets into the tester. Then place the headset on your head and press the Push-To-Test switch. This will power the headphone and microphone circuits. If a complete path of electric current exists, you will hear your voice in the headphones when you speak into the microphone. If testing two headsets, you and the person wearing the other headset will be able to hear each other.
This self-contained unit comes complete with one 9-volt battery, all in a strong, lightweight case.