Its performance is rather surprising! It definitely silences the sound while playing, it reduces several frequencies and makes practice easier in places where loud instruments are not allowed. It is a bit heavy, which makes it kind of dangerous, in case it falls on the instrument per se, but it is very stable once it is fitted on the bridge. However, one of the screws has broken unexpectedly, but I managed to glue it back, and so far, there has been no problem.