Thanks for the questions. I had to drill a 1/2" hole for it. On the front side it uses a spirolock, looks kinda like a very small and thin key ring. On the back are two ears with threaded holes for set screws. So you have a spirolock on the front and set screws on the back side putting tension on the adapter. It is very small and will fit almost anywhere. Here is a
tutorial on mounting it to a MOE handguard.