High-Speed Low Drag: Equip this Holosun HS510C Circle Dot Sight with the HM3X Magnifier Combo to adapt to CQB and longer-range scenarios in a flash. Holosun designed the 510c with the Multiple Reticle System (M.R.S.) that allows the operator to seamlessly switch between a 65 MOA circle with 2 MOA dot, a 2 MOA dot only or a 65 MOA ring only. The Holosun HS510C Open Reflex Circle Dot Sight w/HM3X Magnifier Combo and is powered by both battery and solar energy, and the LED technology allows a single CR2032 battery to provide up to 50,000 hours of operation. These sights are parallax-free and offer unlimited eye relief for the most comfortable experience possible.