Relatively useless

The bristles (whether long or short) can not get into the places that I can not reach with the rag. On the contrary, an old cotton T-shirt will do a much better service here.

In my 10s wreath to get not between the pinion, because the sprocket cleaner is too thick. But even if he had not, I do not see what would make the thing that a piece of wood and a cloth can not.

There are a whole bunch of youtube (German and English) on the video you can see otherwise obvious expert bike mechanic who actually completely helpless "making out" with the "thing" on the rear sprocket. If you pay attention you can see that these men achieved neither with the hook-end even with the bristles, a cleaning effect which goes beyond the one lobe. (Afterwards one is always wiser.) I am forced to the suspicion that this is a covert advertising.

Who wants to have his cassette squeaky clean, will not come around it to expand the cassette and to dismantle or to use a Degreaser. In the latter almost a religious war is raging over whether this is a curse or a blessing for the drive system, as degreaser allegedly removed the lubrication in places that you never get oil or fat and thus at least destroyed the chain immediately. To tell, my expertise and experience but lack the sprocket cleaner is definitely unfit (but certainly not harmful).

I use the side with the long bristles now to clean other hard to reach parts of the wheel. In this respect, the part still has some benefit, why there are still 2 stars but I would have bought it for not.

No buy recommendation from me.