American Defense AD-T1−11 Mount paired with the Holosun HS503GU Red Dot. The Holosun HS503GU features the circle dot reticle. This is a one piece Mount that will Lower 1⁄3rd Co-Witness with standard AR-15 height Iron Sights. Packages are shipped un-mounted in their separate factory boxes. Assembly required. Available only to United States customers, Cannot be exported. Not available to dealers.