It is KM-F basic stationary key of USSR Army-Navy sets.
Several versions: with filter (KM-F) w/out filter (KM)
Bakelite and stiroflex materials versions
Termodependable and termoresistive cases.
Produced by Ukraine situated plant "ZTA" (Zavod telegrafnoy apparatury)

 

GROM telegraph key

 

Inside ...

USSR morse key

 

Label, particular.

USSR telegraph key

 


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