Sig Sauer Romeo-RS Pro 1x31mm 3 MOA Green Dot Pistol Sight - The 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. Featuring a convenient side-mounted illumination adjustment button embedded into the polymer housing to prevent accidental interference; side-load battery tray; MOTAC (Motion Activated Illumination) that powers up when motion is detected, powering down when inactive; 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.