I tested the sander for walls and ceilings in me, it has been a crazy speed. Result impecable, catching up on a few millimeters in a second, I could create the same inminci edges on a plate effectueuse smoothly. However, it should touch the corners because the machine can not enter it. Connected to a vacuum cleaner to middle range chantien I have not had a dust grain on the same face to the ceiling. For an amateur it is the ideal product because I think for the price the engine would tend to heat up for professional use, tested.