The Brownells dovetail scope base enables the modernization of numerous older .22 rifles to accommodate contemporary rimfire optics. Constructed from robust and durable aluminum, it features a black anodized finish that complements blued firearms. This base provides solid and rigid support and is compatible with all tip-off rings designed for 3/8 inches nominal dovetail receivers. It is pre-drilled and countersunk to accommodate three 8-40 screws, which are included. The receiver must be drilled and tapped for installation. Dovetail scope base with anodized finish 100-4 - durable, corrosion-resistant, and precision-engineered for optimal performance and secure mounting