despite the 22mm glue base diameter, when set with a high loft and after use the brush blooms into a similar size to my 24mm brushes. Performance is excellent. Soft tips, some slit scrubbiness from the bristle sides, holds and releases soap and water well. I can't detect any faults. It does the job at a very reasonable price. I set it into a Yaqi Surf handle at a high loft to where the handle just slightly pinches the base of the knots natural splay. The backbone and face splay perform perfectly well. No "wet mop" floppiness.
I wouldn't mind seeing this in an 18-20mm size knot since it performs like a much larger brush than it actually is.