The Tube Amp Doctor 5881WXT-R Tubes are suitable for guitar amplifiers that use 6L6GC type power tubes. These tubes have a more modern and aggressive tone and will give your amplifier a more pronounced upper midrange that will allow your sound to cut through any stage mix. The 5881WXT-R tubes are very versatile, however their sound really owes to heavy, low-tuned playing. Manufacturers that have used these tubes include; Fender, Engl and Mesa/Boogie. The main features of the Tube Amp Doctor 5881WXT-R Tubes include: