The TEL-66T is a noise-cancelling aircraft communication microphone. It consists of a dynamic microphone cartridge, transistor amplifier, and push-to-talk switch in a rugged, black plastic case. A hanger bracket and mounting hardware are provided with the microphone. TEL-66T has a straight PJ-068 plug. TEL-66TRA is identical to the TEL-66T, except that it has a molded right-angle plug. The models TEL-66T and TEL-66TRA are approved for aircraft use under Federal Aviation Agency TSO C-58.