Quote Originally Posted by ben-s View Post
I noticed something on this photo:
When I saw it, I wondered whether the perspex box under the front of the head and roller was for vacuum. There seems to be a hose running to it...

That is the correct design for the vacuum attachment, but I didn't see any hose running to it, nor did I see any catch basin for underflow (or overflow, whatever....) as you tune the flow/vacuum combination. So I discounted it as being an in-use vacuum system. IDK.