Trijicon

Trijicon's signature is illumination without batteries — tritium and fibre optic that simply work whether or not anyone remembered to change a cell. The ACOG built that reputation across two decades of military use.

The RMR is the red dot that most other pistol optics are measured against, and its footprint became a de facto industry standard. This is expensive equipment bought by people who need it to work without being thought about.