Used a few of these, superb for reducing volume and introducing a slightly different tone to your playing. In particular on the ride cymbal, a lovely floaty, airy tone.
However they don't last, in particular if you're not careful with how you play them on crash cymbals they will break up and fracture very quickly. Don't try and use them as a solution for playing rock, but at a lower volume. Instead use them as a choice to create different textures. They are costly if you need to keep replacing them!
