whats the optic on the SCAR?
As someone else already stated, it is a Mepro 21 reflex sight. It has the triangle reticle, instead of the bullseye reticle. You sight it in with the top tip of the triangle.
I like the optic because it uses fiber optics and tritium - so, no electronics or batteries. Its always on. This latest version, Revision M, has solved most of the washout issues these types of sites have previously had. I had tried a Trijicon RX30 and the previous version of the Mepro a few years ago, and did not like them. This new version works extremely well