The Trijicon SRO (Specialized Reflex Optic) is purpose-built for pistols - a clean, open-window design that gives you faster target acquisition and a wider field of view than a traditional RMR. The 5.0 MOA dot is the most visible of the SRO lineup, ideal for fast defensive shooting and quick close-to-mid range engagements. Key specs: Reticle: 5.0 MOA red dot Housing: 7075-T6 forged aluminum, hardcoat anodized Window: 22.5mm round, optically clear Illumination: 8 brightness settings + 2 night-vision compatible Adjustment: 1 MOA windage and elevation clicks Battery: CR2032, top-loading (no need to dismount to change) Battery life: up to 3 years at brightness setting 4 Weight: 1.4 oz Footprint: Trijicon RMR - compatible with RMR-cut slides and plates Waterproof: submersible to 10 feet Footprint compatibility: The SRO uses the same mounting footprint as the Trijicon RMR. If your slide is cut for an RMR or you have an RMR adapter plate, the SRO drops in. Pair with our Calculated Kinetics MOS to SRO/RMR plate for Glock MOS slides. SRO vs RMR: The SRO trades the RMR's enclosed-emitter housing for a wider, open window - better for fast acquisition, slightly more exposed to debris. Most competitive shooters prefer the SRO; concealed-carry purists tend to stick with the RMR.