The HE510C-GR-FDE is a versatile open reflex optic designed for long gun applications. The HE510C-GR-FDE is at home on carbines, PCCs, and shotguns due its durable design. HE510C-GRfeatures and aluminum housing with titanium hood for added shock resilience and includes a QD absolute co-witness mount (1.41 dot height). The HE510C-GR-FDE is packed with Holosun innovations including Solar Failsafe, Shake Awake, MRS (Multi-Reticle System), Green 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.