6N3P-DR (6H3П-ДР ) is a double triode tube of special quality, equivalent of the 6CC42, 2C51 and 5670, which are slightly different but normally replaceable. High reliable, durable and extra long life version of the 6N3P tube. Minimum of 10 000 operating hours (under prescribed conditions). New old stock. Made in years 1983 and 1984.