The Express 5:50 is Mesa Boogie's entry-level line and is equipped with 2x6L6 power tubes and 5x12AX7 pre-amp tubes for that classic American tube tone. The names come from the newly patented 'Duo-Class' power amps, which can be switched between single-ended Class-A mode, with a maximum output of 5W, and the push-pull Class-A/B mode, which gives the rated output power (50W). Truly exceptional entry level Mesa Boogie tube amp. This is a 1x12" combo. Comes with original footswitch and original dust cover (as pictured). Must hear to appreciate. Thank you.