RARE Kriegsmarine Optical Gasmask 'Draeger' + accessories

Certainly one of the very rarest pieces of Kriegsmarine issue uniform related equipment - the optical communication gasmask or Optische Gasmaske M-44 which was produced by Draeger. 
 
This variant of gasmask is very scarcely seen and was primarily issued to KM troops who would operate a variety of handheld binoculars, deck-mounted gunsights and rangefinders etc.
 
This particular example remains in very good, fully supple condition throughout - as well as retaining the even rarer accompanying accessories!
 
These include various interchangeable eyepiece / lens sets to be employed for use with all different optical instruments, as well as the adjustment tool to fit these, and the air filter hose. All of these items come stored within the original 'Draeger' storage canister, which is still intact with all of the internal holding structure (nearly always removed and missing) and the instruction manual in the lid! 
 
The case is also visibly marked 'I/V 3,7' to the base to indicate this set was actually issued for use with a specific 3,7cm Flak gun - such as the 3.7cm SK C/30 gun used aboard both KM surface vessels and U-boats alike! 
 
An incredibly rarely seen piece that makes for a truly wonderful and unique display item in any collection! 
 
*N.B. the display head is shown for display purposes only and is not included.