This is only one half of the Gravity microphone quick-release. If you have some of these, then get extra of this part, so you can have some already fitted to other mics or mic clips, and you can quickly change them over without having to screw mic clips onto stands or booms.
Unlike certain others, this quick-release prevents the mic from spinning around the stand or boom. There is a popular, industry-standard used on many big tours, IMO this one is better. No lever sticking out to get damaged, and less chance of accidentally leaving it unlocked. Strong enough for heavy mics. I use one on a stereo shock mount with 2 MK-012's with the metal swivel adapters and larger capsules, so it's much heavier than most single stage mics, but this quick-release has no problem holding them securely. But, sometimes you have to just give it a little jiggle to be sure it snaps into place. It's still better than older designs though.
It only costs a few bucks so if you are getting the whole quick-release unit, get at least some of these extra couplings. It makes the Gravity QR the best mic quick-release in my opinion, especially at this price