Bought this mute for it's quality, knowing it is being used also in orchestras, myself being only a hobby player in a local church brass band. It is a very well done mute, nice tone, very good pitch.
It was recently used by a professional musician and he was very pleased with it. Copper bottom for sure helps the nice tone. I own it for over a year and it was used a few times, no wear visible and I did not clean it, just handled it carefully.