The ROMEO4H red dot features a durable, shockproof, CNC-machined aircraft aluminum housing with precision-molded aspheric lens technology, which virtually eliminates aberration, reduces weight, and focuses images through the lenses for superior optical performance, while a high transmittance red notch reflector delivers unmatched brightness, eliminates distortion, and maximizes light transmission for optimal clarity. SpectraCoat™ coatings further enhance color fidelity and light transmission for optimal clarity. Powered by an efficient red LED emitter for daylight visibility, 4 integrated reticle options (dot, circle-dot, dot with holds, and circle-dot with holds) offer quick, customizable target acquisition, activated by MOTAC™ (Motion Activated Illumination System) technology, which automatically activates the illuminated reticle when it senses motion, and powers down the unit when the weapon is idle for reliable battery preservation. 12 user-selectable brightness settings (10 daylight; 2 night vision) ensure reliable visibility in all lighting conditions, while the included true co-witness QR mount and low-profile 1913 Picatinny mount readily attaches to most firearm platforms for maximum versatility. The side-loading battery compartment makes it easy to replace the CR2032 battery (included) without removing the sight or affecting zero. IPX7 waterproof.