Stores reference 10A/12572. Distinctive black painted 'ball-shaped' microphone housing with angular metal on/off switch mounted on the top. Complete with remnants of the original wiring loom and rubber grommet at the point where the loom enters the housing. It retains approximately 50% of the original paint although this is rather dulled. The switch is seized but it could probably be freed with some penetrating oil. The wiring loom securing tab is present but corroded - see photographs. Type 27's (more commonly known as the Type 28 when 'mounted' on a wiring loom) were sometimes used with the E-series and type G oxygen masks in addition to the second pattern microphone carrier masks. A reasonable used example. Stock code O19650.