It's a Mesa Boogie Studio Caliber. I've had two Calibers previously, both were the 50W DC-5 version. The first one sounded great, but the master volume was a bit weird. It went from totally silent to totally deafening in the smallest increment of the knob. Nothing in between, so impossible to use at rehearsals or whatever. I sold it, but I missed it. Better cleans than anything I've heard except my Hiwatt, and righteous punky gain sounds, and you could lift it with two fingers. So I bought another. Guess what? It went from totally silent to totally deafening in the smallest increment of the MV knob. So I sold it. I happened across this one last week at a reasonable price. Its the 20W version. So far, I've managed to play it at less than deafening levels at home, so that's good. Looking forward to trying it in a band setting.