Wonderful Soviet, dynamic, cardioid microphone. Production began in the early sixties. Frequency response from 50 Hz to 15000 Hz, frequency response unevenness 12 dB, Nominal impedance 250 Ohm, Standard level of axial sensitivity -78 dB, Average sensitivity difference between “front” and “rear” 12 dB. On the plant’s website it is written that this particular microphone (and also MDO-1) was equipped in the Kremlin Palace of Congresses in the early sixties.
Also check out my lots in my store, there are a lot of interesting and original things there.