I don't like to post a review unless I have new information to add.  So... the only thing I would add to the other reviews on this item is that what I said in the title:  Heavier microphones may bounce a bit when using these mounts.  The plastic is sturdy to stay in place, but a bit flexible.  It has to be to allow you to bend the clip over the rim of the drum.  I use different mics for different drums and noticed that a Shure SM57 stays in place pretty good, but other mics I've used (including the Sennheiser MD 421 and others) tend to cause the end to flex under the weight of the mic--especially when miking the resonant side (bottom head) of the snare.  So if you use heavier microphones than SM57s, be aware that they could bounce a bit during recording/performance.