CYMPAD Moderators Set of 2 x 90mm Set of 2 x 60mm The 90mm set is unopened. The 60mm set has been opened, but was only tested once in a studio and is in almost new condition. They provide a muting effect when attached in place of the felt on a cymbal stand. You'll understand when you try them, but they provide a fairly strong effect. Of course, the effect varies depending on the size, weight, and type of cymbal, as well as the desired muting level. There's no other way to know than to try them, so please give them a try if you'd like. I play in multiple bands, so I bought several sizes mainly to adjust the overtones of my ride cymbal. In my case, the Optimizer, a smaller product than this, suited me better, so I use that instead.