The Precision Rifle ABR (Patented) has been designed from the ground up to be a direct replacement for the lower picatinny rail on both the Ruger Precision Rifle (RPR) and RPR Magnum. Two lower riders are designed to provide optimal performance when used with a rear bag with ears. Made in the USA from American 6061 Alum and finished with Class II Anodizing they are less than 16oz. NOTE: The Long Shot Precision Recoil Plate is not required. Installation Instructions included with purchase Required tools: 9/64 Allen wrench (0.140) 5/32 Allen wrench (0.156) Please note that this product does not fit the Ruger Precision Rimfire Rifle. Installation Instructions below: Remove recoil pad screws (9/64 Allen wrench) Remove lower recoil plate screw (5/32 Allen wrench) Loosen slightly the upper recoil plate screw eases alignment later Open the lower cam lever Ensure the stock length lock plate is lifted by the internal spring Unscrew the nut on the cam lever one full turn to open the clamping range Put a small pencil mark on the nut to ensure one full turn is completed Remove lower picatinny rail by sliding it towards the pistol grip It will be necessary to fold the rear stock to 90 degrees Slide the ABR into the clamp and up to the recoil plate Tighten the lower cam lever (adjust nut if needed to ensure a firm clamp) Install the lower bolt through the recoil plated into the back of the ABR and tighten. Tighten the upper recoil plate screw. Reinstall the recoil pad.