Holosun Technologies HS510C Open Reflex Circle Dot Sight and HM3X Magnifier Combo Pack, Hard Case 510C+HM3X The HS510C is an open reflex optical sight designed for rifle and carbine applications. Features include Holosun's Super LED with up to 50k hours battery life, Multi-Reticle System, Solar Failsafe, and Shake Awake. The HM3X is An Aluminum bodied 3X magnifier that includes a quick release, ambidextrous, flip-to-side mount with Absolute and Lower 1/3 Co-witness mounting solutions. Additional features include 2.75" of eye relief, IP67 certified water resistance, with windage and elevation adjustment for precision zeroing.