Manufacturer : Telefunken Type : E.H. 333 Produced : 1925  Germany  Device : high impedance headphones 2x 2000 ohms Operational estimation (1-10) : 9 Global estimation (1-10) : 7 Designed : aluminum, backelite and copper Specials : early euro - germany model for commercial application        - adjustable metal diaphragmas        - later exists similar model with bakelite shells used during WW2 Note : wanted sample