This Ruger Rifle 10/22 base mount with screws is lightweight Weaver/dovetail scope mount. Scope mount is dual purpose base for the Ruger 10/22 it can take both Weaver and 3/8" dovetail rings. Fits the pre drilled holes on top of your 10/22 rifles receiver and it is easy to install. Made from Black anodized aircraft grade aluminum. Accepts all standard 3/8" Dovetail, Weaver / Picatinny 1913 rings. Limited Lifetime Warranty. Comes with all mounting hardware.