Stores reference 10A/9004. This is the bell-shaped carrier (casing) for the type C carbon microphone. Within this the actual microphone componant was mounted. Part of the carrier is sprayed with powdered cork which acts as an insulator against condensation and noise. To the base are two moulded breathing vents and there is a slot at the top for a toggle switch. This example is in reasonable condition. It retains good overall shape and being alloy, can easily be re-shaped where necessary. It is unusual in having a number '30' deeply stamped in the alloy. Note that you are buying the carrier alone. The microphone is not fitted, none of the original chamois covering remains and the brass mounting bracket at the base is absent. These microphones were used with the cloth type D oxygen masks and pre-date the flat-fronted type 18 (type 19 when mounted/wired). Photographic evidence suggests they saw considerable use during the Battle of France. A good starting point for a restoration or 'mock-up' display. Stock code O16655.