Microphone, Linear, M-162/AIC is a noise-cancelling dc powered, high gain microphone designed for use on a headband type headset at low altitudes or for use in a pressure type oxygen helmet, at altitudes where the use of an oxygen helmet is required. The microphone is intended for use as a part of the airborne communication system which will provide communication of high intelligibility under the extreme noise conditions encountered in military aircraft. The preservation, packing and marking specified herein are intended for direct shipments to the Government. However, this specification may also be used for the preparation of microphones for shipment from the parts contractor to the original equipment manufacturer.