The HOLOSUN HS507-PROMAX Pistol Reflex Sight combines a larger objective size with an enhanced sunshade and Performance Reticle System to deliver the ultimate in speed and precision for today's optics-ready pistols. The Performance Reticle System features a 2 MOA dot with 8 MOA, 20 MOA, and 32 MOA circles, alone or combined, to match your shooting needs. Like most Holosun red dots, it comes with Solar Failsafe technology that keeps the optic operational during a battery failure as long as natural or artificial light is available. It still features Shake Awake technology that brings the unit to life with the slightest touch and deactivates when it senses inactivity providing up to 100,000 hours of battery life on a single CR1632 battery. And it's still rated to IP67 waterproof standards. Trijicon RMR footprint. 1 MOA adjustments for windage and elevation. Enlarged viewing window with forward-leaning sunshade to cut glare Precision Reticle System with 2 MOA dot and 8/20/32 MOA circles 7075-T6 aluminum housing 5,000G vibration resistance Manual brightness control with 8 daylight and 4 night-vision settings Shake Awake technology Side-loading battery compartment Up to 100,000 hrs. battery life on one CR1632 battery Waterproof to IP67 standards Trijicon RMR footprint