Bought about 5 of them, while was collecting stuff for my home studio. But about half year I finally assembled the kit, used these. And I have the following to say:
Pros:
they are cheap, comparing with other mounts or stands.
They actually do the job of holding mic on a hoop.
They have a metal body, which allows to bend it a little to adjust the angle. So it is not just a plastic clip.
Cons:
2 main parts are made of plastic: connection to the hoop itself (from top and bottom) and connection between mic holder and hoop attachments (these 2 bolts - it is glued, not a throughout bolt+nut connection). The 2nd part on 1 of my items got broken very quickly, as soon as I tried to use it.
They are sufficiently big over the drum, so if you have tight setup, height of clamp + mic + connector = it might be an issue.
They are not designed for a thick hoops. It fits Pearl 2.3 hoop, it barely fits DW True hoop, it does NOT fit Tama die-cast hoop. To clamp it on my Tama Starclassic Maple toms I had to cut few mm of plastic in the top clamp part to make it deeper.
So.... think twice about purchasing this.