The Russian Zenit EM 35mm SLR was part of a long running series of Zenit cameras and was an upgraded version of the Zenit E, adding automatic diaphragm stop-down with appropriate M42 lenses and a shutter release separated from the winding lever/film counter. Produced between 1972-1984 by KMZ[1].
The EM was also sold by Kalimar as the SR300, and badged as the Cosmorex SE. It was available in both black and chrome finish.