Machined in 4140 steel and melonite coated, OPF-P320, RMR, RSD is a new member of our OPF (Optics Platform, Forward Controls) line. OPF-P320, RMR, RSD is a drop in adapter for superb Trijicon RMR sights. OPF-P320, RMR is shipped with two 4-40x3/16 Allen screws (plate to slide), a 3/32 Allen key, two T10 5-32x3/8 screws (sight to plate) and a packet of VC-3. Torque values: Plate to slide: 6 inA lb; Sight to plate: 12 inA lb Billet machined in 4140, Melonite coated. OPF-P320, RMR, RSD is a Forward Controls Design and Tangodown collaboration. Proudly designed and made in the USA. NOTE: OPF-P320, RMR, RSD was designed and made for Trijicon's Mfg: Forward Controls Design