TruGlo Mounting Adapter 3/8" to Picatinny Weaver Style 7/8" Rail - TG8953BpThis converts 3/8-inch dovetail base (as found on many .22 rimfire rifles) to standard Weaver base. Mounting hardware includedTruglo TG8953B 1-Piece Base For Weaver Style, Black:brType: 1-Piece BasebrModel: Weaver-Style BasesbrStyle: WeaverbrFinish: BlackbrMaterial: Aluminum