Stores Ref. 10A/12572. Distinctive black painted 'ball-shaped' microphone housing with angular metal on/off switch mounted on the top. Complete with rubber grommet at the point where the wiring enters the housing. Grubby and with quite a bit of paint chipping - perhaps approx. 50% plus of the original paint remaining. Remnants of the original loom remain in place. The switch appears to be siezed but lubrication would probably free this. The type 27 (more commonly known as the Type 28 when 'mounted' was sometimes used with the E-series and G-type oxygen masks in addition to the second pattern microphone carrier masks. Stock code O15291.