It just fell apart - NcStar Ar15 Qr Weaver Mount/ Cantilever Scope Mount Rear Ring 30mm

For the money, it's a great way to swap sights between applications. I think I have 5 or 6 including the ones still in the boxes. When you're swapping sights between different weapons, it makes for an easy test drive of the different sights. The rail alignment pin in the front is just press fit from one side and not even threaded. If that comes loose, which it can and does, you can loose forward and backward lock on the rail and the scope may even fall off. Poor design, or poor manufacture, or both. Again for the price they're great, and if you catch the pin before it falls out, or just center punch it in place you'll be golden.
Pros: easy off, easy on, maintains its sighting
Cons: press fit pit, that just fell out.

This review was written in the old system and had content requirements that are different than reviews written today.