With the MOS, I understand that you need shorter screws to mount the RMR to the mounting plate. Do I also need one of these: Trijicon Sealing Plate/Screws

I've watched videos that don't seem to require it, but I've read threads saying that it's necessary.

ETA: failed to mention it's a battery-powered Type 2 LED

Yep, you need that one. It's a shame trijicon doesn't include them with the RMR.

I wish it was included... but Trijicon makes a MOS Glock specific package that is pretty cheap.

Under 20$ on Amazon.


Edit to add:  It worked great on the 2 RMR's I mounted on MOS Glocks in my safe.

Aternarively you can get a similar product from battlewerx with the correct rmr screws.

http://www.battlewerx.com/anti-flicker-sealing-plate-mos-mounting-kit-for-rmr-black/

I like the battlewerx version since it has bump in it to help push the battery into contact. While the type 2 shouldn't need it as much it's a nice design feature and also it's cheaper than the trijicon version.

I purchased this recently and happy with the item.

Thanks, everyone