The Crimson Trace HRO(TM) (Heavy Recoil Optic) is the next generation of quick acquisition tactical reflex sights. Packed with best-in-class features like CT Motion shake-to-wake sensor and integrated Pic Rail mount, the HRO(TM) looks good and performs even better. Universal Pic Rail 2 MOA Dot 50k hrs run time CT Motion Sensor Aluminum Construction IPX7 Waterproofing 8.5 oz with battery