Talley Lightweight Alloy Scope Mounts feature rigid, one-piece construction and a design which eliminates the possibility of a crooked interface between the base and the action, an issue which can affect two-piece designs. This feature provides added strength, enabling them to be stronger than steel rings and bases, but at a fraction of the weight. Extruded from 7000-series aliminum alloy, CNC-machined, and anodized for long-term resistance to the elements. Talley Aluminum 30mm Kimber Model 17, 22, 82, 84 & Cooper Model 21, 38, 51, 57M High Scope Rings 750749