Soviet double triodes 6N3P-DR (6H3П-ДР ) are tubes of special quality and 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 tubes. Minimum of 10 000 operating hours (under prescribed conditions). New old stock tubes, which were completely tested and measured with the RoeTest V10 tube testing system. Matched pairs were selected from a higher amount of tested tubes. Made in the period from 1982 to 1985. Will be delivered in modern white boxes.