Stores reference 10A/11994. Black painted alloy microphone, often referred to as the '1941' pattern although actually introduced in October 1940. Also known as the 'type 21' but this is the reference given to it when fitted to a wiring loom. The casing is somewhat distorted and paint chipped but alloy is quite easy to reshape. The rivet on the lower section of the switch/loom retaining strap is missing and has been secured with wire - see photogrpahs. Air Ministry and King's crown markings. These microphones were used in conjunction with the type D cloth oxygen masks. A fair used example. Stock code H4606.