I've used up the brush that came with the original Bergeon scratch-pen, cleaning up the stainless steel bracelets on a few watches. Easy to use and t has been easy to use and produces good results. These refills should last me a lifetime now. Fitting required a pair of pliers to remove the stub of the old brush. the new one pushed in with a little bit of effort. No problem at all for anyone with the ability to remove a strap with spring-bars.