My hoses have the part no HC215 24-22 MFR 13560. Each end has a cured rubber fitting, and they are only available in one length. Kevin said they are from the States, used with Air Force fighter pilot's oxygen masks.
The claim is they are indestructible, although John Thornton has broken two so far, and the US supplier will not up hold the warranty claiming "diving is a too extreme use of the product".