Engineered for short action Ruger American rifles, this one-piece picatinny scope base is tailor made to match the factory scope mount holes on the receiver. The MIL-STD picatinny slot-and-rail spacing accommodates picatinny or Weaver scope rings. Precision machined from billet aluminum, the base boasts a 6 inches length and a hard coat anodized finish. It includes (4) TORX mounting screws and a T-10 wrench. Proudly made in the USA, this is an authentic Ruger factory accessory.