I've never even seen another one of these! Produced in association with Steve Lukather. It was designed to give more bottom to your guitar tone. It can be used with any tube or solid state amp (not just Riveras). It is easiest if you have an fx loop or line output on you amplifier, but can run paralleled off the speaker output if need be. 300 watts into a phenomenally heavy JBL driver. Comes with a snazzy cover and wheels! Excellent condition. Great for studio use. Add some bass to your champ!! OBO Might consider trades or part trades for other cool Guitar / Tube amp stuff. Even non functional amps if they are good enough. Try Me!