Soviet Union
 
KGB border guard officerís service visor cap
I first discovered this capís true identity quite recently. Only KGB border guards have this unique green top. Ordinarily, KGB caps are dark blue. For parade use, the larger wreathed cap badge is used. Enlisted men have a black chinstrap with a regular enlisted badge. By the way, I need an extra officerís chinstrap, so if you have one, please let me know.