There is precious little room in the space between shells on a drum kit. Often engineers resort to some pretty extreme and/or creative methods to achieve their desired mic placement, including lots of things that involve copious amounts of gaff tape. One that I’ve seen many times, and possibly the simplest, is to just tape two mics together to use them on a single stand. This can work, provided that one or both mics isn’t awkwardly shaped and puts them at odd angles to each other, because keeping them in phase together requires that you have the diaphragms lined up.
So now there’s The X-Clip, and I’m sure you can imagine what it’s good for – it makes it simple as hell to clip a 57 or i5 to a small diaphragm condenser mic so you can use both on the same source while keeping them perfectly in phase, without any tape.
In this video, Furious Glenn Fricker, the Scourge of the Great White North, spends some time demonstrating the use of the clip on a snare drum, with impressive results.