The helmet shown at the black and white photographs here below was made in 1956 as a prototype for a mix gas diving helmet. The constructor of the helmet was Kaj Undén who worked for the ‘Karolinska Institute’ in the nineteen fifties. This helmet is now in the possession of the Karlskrona Navy Museum.

It is not sure what the history of this helmet is except that I bought it at an auction abroad several years ago but it is sure that it came from Sweden. The helmet resembles to the helmet shown above which is in the store rooms of the Karlskrona Navy Museum, and it was built using the same techniques as this helmet ( see the black and white photographs )  Since both helmets are manufactured with the same materials it was assumed that this helmet comes from the same maker until in 2015 a link to a french website was sent to the mailbox of this website: please check the chapter of the French DULAM company for more info.