Holosun Advanced Rifle Optic Sight with Shake Awake, 22mm Optical Window, 12 Brightness Settings, Co-Witness & Low Mounts IncludedARO CORE RD2 (2 MOA Red Dot) ARO CORE GR2 (2 MOA Green Dot) ARO CORE GD2 (2 MOA Gold Dot) ARO CORE RD2 FDE (2 MOA Red Dot FDE) ARO CORE MRS RD (Multi Reticle Red Dot) ARO CORE MRS GR (Multi Reticle Green Dot) ARO CORE MRS GD (Multi Reticle Gold Dot) Advanced Dot System for Enchanced Precision The Advance Rifle Optic Holosun's next gen dot optic, combining trusted design elements from the 403 and 503 series with a wider 22mm window and a crisp 2 MOA