Stores Ref. 10A/13425. Black rubber adaptor ring which enabled the use of the type 25 (10A/12570) and type 27 microphone (10A/12572) with the Type-D oxygen mask. This example is in poor condition - hardened, cracked and not very flexible at all. Whilst it remains largely complete it is suitable only as an example of its type and would not be good enough to fit to a mask. A rare item to find. Stock code O7898.