Ultimate Arms Gear Tactical Black Anodized Aluminum Ruger 10/22 10 22 10-22 Rifle Base Scope Sight Top Dual & Dovetail Predrilled Receiver Rail Mount Adapter This Ruger 10/22 scope mount fits the existing receiver holes and provides a base for both 7/8" Weaver Picatinny devices/mounts/rings as well as 3/8" dovetail for versatility and ease in utilizing both rail styles. Includes mounting hardware Length 4.7" Weight 1.3 oz Black Anodized Aircraft Aluminum Finish