I am pleasantly surprised at the good quality at this price. Ordinary metal thread to stalk and scrubber connect the two parts really good! I use the small to clean carpet with tons of carpet powder which I scrubber with the einbürste and this works fine. I drilled a precaution on the fast a hole with M4 thread and the stem additionally secured with a screw. bombproof, but that was actually even before that way. the scrubber is worth a big recommendation !!!