The Sig Sauer ROMEO-RS (Reinforced Steel) was specifically engineered to provide the accuracy and convenience of a pistol-mounted red dot at a cost that competes with high-end iron sights. Inspired by the design of modern striker-fired pistols that employ high-strength polymer and metal, the ROMEO-RS housing forms around a rugged steel chassis that supports and protects a premium aspherical glass lens. Threaded metal inserts allow for optimal torque load when mounting the optic to a pistol slide and installing the side-load battery tray, while additional metal inserts provide increased accuracy and long term durability for the windage and elevation adjustment mechanisms.The ROMEO-RS features a convenient side-mounted illumination adjustment button embedded into the polymer housing to prevent accidental interference, and the side-load battery tray makes battery replacements easy to do while maintaining zero. SIG SAUER's updated footprint design maintains true compatibility with industry-standard optics cuts while allowing for the additional lock-up strength provided by steel recoil pins to eliminate the potential for any lateral shift.Built in Tualatin, Oregon, the ROMEO-RS was engineered to deliver premium red dot functionality at a cost that's within reach of any shooter. Hybrid design featuring a skeletonized steel chassis, molded into a high-strength polymer housingPremium molded glass ashperic lens for a distortion-free sight pictureHigh efficiency point source LED emitter with 8 individual brightness settingsLarge side control button for easy reticle adjustmentsConvenient side-mounted CR1632 battery tray with security screw for easy access without removing the optic from the firearmMinimum continuous runtime of 20,000 hours (at medium setting, dot-only)MOTAC (Motion Activated Illumination) that powers up when motion is detected, powering down when inactiveDesigned, developed, tested and assembled in the USAFully Backed by SIG SAUER's Infinite Guarantee