Quality, rugged, simple, reliable and expensive. get what you pay for - Trijicon RMR Dual Illuminated 9.0 MOA Green Dot Reflex Sight

This is my second Trijicon RMR with green dot. I prefer these as they do not require batteries and are extremely rugged. My first one is about 10 years old now and looks/functions like it's new. Yes, there are less expensive options available; however, I stick with this based on experience and quality. The ability to work without a battery can not be understated as a benefit - especially if you have multiple sights and batteries in your safe. Highly recommend.