The HS510C FDE is a versatile open reflex optic designed for long gun applications. HS510C is at home on carbines, PCCs, and shotguns due its durable design. HS510C features and aluminum housing with titanium hood for added shock resilience and includes a QD absolute co-witness mount (1.41 dot height).HS510C is packed with Holosun innovation including Solar Failsafe, Shake Awake, MRS (Multi-Reticle System), Red Super LED with up to 50k hour battery life, with 10 daylight and 2 night vision compatible intensity settings. A lower 1/3 co-witness spacer is available separately from Holosun dealers that increases the dot height to 1.63. IP67 waterproof.