If you want a pistol dot and you do not want a menu of reticles, start here. It is one 2 MOA red dot on the RMR footprint, the cut you already see on a lot of compact and full-size slides. There is no circle to switch on. Turn it on, find the dot, and shoot. If you decide later that you want a ring to pick up faster on the draw, the 507C is this same housing with a circle-dot.

The housing is black anodized aluminum, and the CR1632 loads from the side. That is the detail people appreciate after the first battery change: you do not have to pull the optic off the slide and start over on zero. Solar sits behind the glass as a backup, and Lock Mode keeps a holster from walking the brightness buttons while you carry.

Holosun lists a 0.63 × 0.91 in window, 1 MOA clicks, 50 MOA of windage, 10 day settings and 2 night settings, and a 50,000-hour battery rating. It is waterproof and parallax-free. Eye relief is unlimited because the dot is projected on the glass, so you can run it as close as the slide allows.

The emitter is open. Rain, lint, and mud can land on the LED. If you want that window sealed, the EPS is the enclosed optic in this size. It bolts directly to an RMR-cut slide. A Glock MOS or other optics-ready gun still needs the RMR plate made for that slide.