The SIG-LOC(TM) (Leverage Optimized Connection) system was first concepted during the development of the ROMEO-M17, revolutionizing pistol-mounted optic integration with a low-profile, ultra-tough connection between the optic and pistol slide. Designed for precision and strength, SIG-LOC(TM) ushers in a new era of expectation and performance for civilians and professionals with the ROMEO-X SIG-LOC pistol-mounted red dot.SIG-LOC(TM) is an innovative mounting footprint that establishes five points of contact between the slide and optic to eliminate shift in zero created by extensive shock from recoil and harsh impacts. The unique bottom-mounted design allows for a longer focal length that dramatically reduces parallax and reticle distortion to provide an incredibly forgiving shooting experience.With SIG-LOC(TM), you're investing in technology that has been vetted and trusted by the most demanding users in the world, ensuring superior accuracy and reliability in every situation. Inspired by MIL-SPEC ROMEO-M17Establishes 5 total points of contact to create the strongest lockup in the industryLonger focal length to dramatically reduce parallax and create an ultra-crisp reticleRugged 7075 aluminum housing with a fully enclosed and sealed optical systemDistortion-free aspherical glass lensMOTAC (Motion Activated Illumination)Industry's lowest deck height for standard-height iron sight co-witness20,000 hour battery life with side load battery15 illumination settings including 3 dedicated night vision*Please Note - Optics utilizing the SIG-LOC(TM) mounting footprint are NOT compatible with legacy P365/P320 models that use the standard RMSc mounting footprint. Please verify your pistol is SIG-LOC(TM) compatible.