Holosun Technologies 512T, Red Dot, 1X28MM, Black Finish, 2 MOA Dot with 65 MOA Circle, Titanium Housing HE512T-RD The HE512T-RD is a versatile open reflex optic designed for long gun applications. HE512T-RD is at home on carbines, PCCs, and shotguns due its durable design. HE512T-RD features a housing made of Grade 5 Titanium and includes an absolute co-witness mount (1.41" dot height).