extension/slave amp?

Hi there... quick question... I seem to recall a while back seeing a mesa boogie "extension" or "slave" amp on eBay... it was a 1x12 combo with no preamp or tone controls, just a volume and maybe a presence knob... it wasn't just a cabinet, it actually had a poweramp in it... I even want to say it was a version of the 50 caliber plus, but I'm not sure...

Anyway, am I just dreaming this up or are they real, and what are they most commonly known as?

Any response is appreciated... thank you...

Simul-Satellite. It was meant to be paired with a Mark IV but will work with other amps too.

I would love to find one of those! Looks like the perfect amp for a pedal based rig. Now that Boogie is in the pedal biz they should look into marketing something like this again.