Sig Sauer Romeo 4B 1X20 MM, 2 MOA Red Dot/ 65 MOA Circle Dot Battery Powered with Low Profile Torx Mount Romeo4 sights are parallax-free so point-of-aim is point-of-impact and the red dot remains parallel to the bore of your firearm, no matter what your viewing angle is relative to the optical axis of the sight Dual reticle option, on select models, toggle between 2 MOA red dot or circle dot (2 MOA red dot with 65 MOA circle) Unlimited eye-relief allows you to acquire the aiming point and the target regardless of the position of your eye behind the sight Features our MOTAC (Motion Activated Illumination System) that powers up when it senses motion and powers down when it does not. Provides for optimum operational safety and enhanced battery life Extremely strong and lightweight aircraft grade CNC Aluminum housing ensures a lifetime of reliable service