Replace the old part number: 18920G-02 with the new part number: 18920G-04

The David Clark Company Amplified Dynamic Microphone is a noise cancelling type designed to operate in place of carbon and amplified dynamic microphones.

This microphone will not operate in circuits that do not supply a DC bias voltage. Most modern aviation communications equipment do supply this required voltage. If you are not certain, consult your radio technical manual or with your avionics shop.