MIL-STD 1913 Picatinny rail is machined from lightweight TennalumA(R) 7068 alloy that gives the same strength as steel with only A /A^3 the weight. All contact surfaces are stress relieved and pre-ground before final machining to exact MIL-STD 1913 dimensions. Integral recoil lug and elongated mounting screws let you position the rail so the lug will bear properly against the receiver to prevent the rail from moving even under aggressive recoil. Built in 20 MOA of elevation for extended long-range shooting. All surfaces are fully chamfered, with extra clearance over the ejection port. Mfg: Precision Armament SPECS: TennalumA(R) 7068 alloy, hardcoat anodized, matte black finish. Instructions and 6-48 mounting screws included. Short Action (SA) - 6A 1/2" (16.5 cm) long, .380" (9.4 mm) high at front ring, 2.3 oz. (.65g) wt.