Vintage and rare matched pairs of 6S8S triodes from manufacturer Svetlana, St. Petersburg. Direct replacement for the american 2C22 tubes. New in box. Pairs were selected out of a bulk of tubes, which were measured with the precise RoeTest V10 tube tester (samples of the matched pairs are in the gallery). Original datasheet is available for download. OTK stamp. Year of production: 1960.