The Ruger 10/22 and .22 Charger Pistol factory scope rail is a genuine Ruger factory accessory. This picatinny scope base measures 4.62" and comes with four mounting screws. It is made to Ruger specifications, using the same manufacturing and materials as the original equipment parts, ensuring perfect fit and operation. Specifications and Features: Ruger 90465 10/22 and .22 Charger Pistol Rail Genuine Ruger Factory Accessory Picatinny Scope Base Mounting Hardware Included Matte Black Finish Fits: Ruger 10/22 and .22 Charger Pistols