I got mine used a few years ago.  $100.00  They did not know what it was.  I bought it just looking at a picture.  Figured I would not be out too much. Took a chance and love it.
It is an older model though.   The handle is only one side.  A little flimsy.    after I got it I started looking for parts, just in case. Drew? I think , at  
Excellent supply said they could get parts if needed.
I use it mainly for pre-scrubbing  prior to HWE. Trashed rentals.   Many times because of the nice look while scrubbing the customer thinks the clean has already been done.  
Though sometimes post scrubbing Kil -Odor plus for odor. It has solution tanks, gravity feed. 
The brushes push the debris toward the center. 
I think the Brush Pro type pushes toward the outside, to be captured in trays?