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 indust...