Rare Festungsfernhörer 39 doppelt headset

Rare coastal artillery related headset that plugs into the FF33 field phone and desk phone. The headset shares many optical similarities with the Panzer variant but the cable is different; unlike the standard Y-shaped cable setup this example has the cable for the second speaker running over the top of the headset. There are many variants of these headsets but this example is for sure one of the rarest to find!

More information; http://www.rkk-museum.ru/documents/archives/images/D796-1940.pdf