Electron tube STR85/10-C is a voltage regulator 85±2V (at a current of 6 mA) from manufacturer RFT. Allowed current range is 1-10mA. STR85/10-C is very similar to the STR85/10, 0G3, STV85/10 but it has a different pinout, so it is not a direct replacement. All available pcs do have the Q1 quality mark. New old stock tubes in original boxes. Year of production: 1967.