Holosun 507K is by far the best micro red dot sight for Glock 43X MOS (RMSc footprint). It is really designed for slim profile handguns, and its the same width since the Glock 43X slide without sticking out on the sides. Simple to deal with recoil over the vary, straightforward https://glock-43x-mos-frame46790.thenerdsblog.com/22623478/indicators-on-glock-43x-mos-red-dot-you-should-know