The Mesa/Boogie 6L6 STR 440 Duet amplifier tube matched pair gives your amp the best 6L6 performance possible. Consistent and reliable, the STR 440 Duet features the same tubes Mesa puts in all their 6L6-equipped amps. These matched tubes give you punchy bass, great-sounding mids, and detailed high-end while providing a rich character that serves your rig well — from crystal clean all the way to dialed-up leads. Great for all playing styles, these tubes help you get the most out of your amp. Use what Mesa/Boogie uses to power their amps: the 6L6 STR 440 Duet!