In case anyone doesn't know what I'm talking about, here it is

So I've never owned a scout light, but it looks like it attaches to the base via two screws. So how do you get this Geissele mount attached to the rail, and then the Surefire attached to the mount. It looks like one would block the other, if this makes any sense. I'm probably missing something here but I've been looking at this as a setup for my rifle I would like to understand before I buy it.

It comes with a few different mounting options and heights to clear buis and accessories depending on where you plan to place the light. There is a backer plate that fits on the inside of the rail. The screws go through the backer plate, mount if you choose to use one, and directly into the body of the Scout light (they are threaded).

You will have to remove your rail from the barrel nut to do the install.

I personally prefer the Unity Fusion Micro hub for an all-in-one light/buis solution.

Thank you! That makes sense and is exactly what I needed to know.

If you have an older rail, that this is designed for( I have a MK2) Mlock accessories will work. I have a Arisaka Mlock inline scout mount out front on the left side.