HOLOSUN 507C X3 OPEN PISTOL REFLEX SIGHT The Holosun HS507C-X3-RD-MRS updates the proven 507C platform with a reinforced housing, advanced brightness control, and Holosun's Multi-Reticle System in a compact optic built for modern pistols. Designed around the RMR footprint, it delivers a low-profile solution that works just as well for everyday carry as it does for duty and range use. A forward-facing photodiode pairs with Solar Failsafe to automatically manage brightness as light changes, while manual controls with memory and lockout give shooters full authority when needed. Powered by a side-loading CR1632 battery rated up to 100,000 hours and backed by Shake Awake, Mfg: Holosun