A 12 bolt Diving Helmet,
Possibly by Siebe Gorman, numbered 17532 on the faceplate. The bonnet with screw faceplate and two barred side windows, air inlet, exhaust and telephone socket, locking pin and manual spitcock. Internal microphone and chin switch. The corselet with split brailles, and weight nipples, no makers plate. 18in (46cm)high.