Compatible with virtually every rail-equipped long gun, the Sig Sauer® ROMEO7S 1x22mm Compact Red/Green Dot Sight features high-performance lens coatings for excellent light transmission, color fidelity, and contrast in any environment. The 2 MOA illuminated dot reticle offers lightning-fast target acquisition, while the intuitive rotary dial allows you to choose between a red or green reticle for added versatility and maximized clarity. Built-in MOTAC™ (Motion Activated Illumination System) technology automatically activates the red dot when it senses motion, and powers down when the weapon is idle for enhanced battery conservation, delivering an impressive 50,000-hour battery life on a single AAA battery (not included). The shockproof, CNC-machined 6061 aircraft aluminum housing delivers lasting durability and superior corrosion resistance and comes ready to mount to standard Picatinny rail systems with an adjustable ½” hex mount (1.41” and 1.63” sight heights). IPX7 waterproof and fog-proof.