The Sovtek brand of military grade vacuum tubes are made in Russia and considered to be among the finest currently available. 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. It yields a 20% higher output than the Sovtek 5881WXT and offers superior tone and overall performance to any 6L6 or KT66. The ultimate 6L6, the WXT+ will improve the sound of any 6L6 guitar amplifier.