Precision Reflex PRI Delta Replacement Top Rail Forearms 5in Black. 5 Inch Replacement Forearm Rail with 1913 rail configuration. Rails have a 2'' radius conture cut on bottom side to mate up with 2'' tube. Rails are constructed of T6 6061 hard coated black anodized aluminum. The rail comes with 4 mounting screws and 2 bar nut for installing. Specifications for Precision Reflex PRI Delta Replacement Top Rail Forearms: Manufacturer: Precision Reflex Color: Black Fabric/Material: Aluminum Cant: 0 MOA Gun Make: AR Platform Package Contents: Precision Reflex PRI Delta Replacement Top Rail Forearms Precision Reflex 05-071-5T: PRI Delta Replacement Top Rail Forearms 5in Black