Electron tube 6N2P-ER (6Н2П-ЕP) from manufacturer Voskhod, Kaluga. High quality triode with low microphonics, which is very close by characteristics to the 12AX7/ECC83/E83CC tubes and it may be used at the same positions. But be careful, it is not a direct replacement. 6N2P-ER has 6,3V heater voltage and would need a different wiring than the standard 12AX7/E83CC tubes. Military -ER version, long life (more than 10 000 operating hours), high reliability tube. Tubes are unused and tested. Made in the end of the 70's.