These are the OEM version of the Sovtek 6L6WXT. They are unlabeled and without retail boxes because they were intended to be used in new amplifier production and were supplied in bulk cases of 100 tubes. Modeled after the vintage RCA 6L6GC “Blackplate” the Sovtek 6L6WXT features larger plate dimensions and improved grid structure for increased power handling capabilities. The 6L6WXT also features mica spacers with metal springs to eliminate tube rattle and microphonics. The Sovtek 6L6WXT yields a 20% higher output than the Sovtek 5881WXT and offers superior tone and overall performance.