Almost certainly made by the most famous name in diving Siebe Gorman as issued to Royal Navy hardhat divers. Stamped with Ref. No. 6230-99-942-7885. Fitted with original leather wrist strap. Chrome finish in excellent condition over brass body. Sold as a collectors item but we have tested with batteries and is in good working order although after all this time we can't guarantee it will still be waterproof at 50 metres! 1.5" (28 cm).