The one-piece construction of the Talley Lightweight Alloy Scope Mount is unique. The Talley Lightweight unitized design eliminates the possibility of an ""out of alignment"" interface or ""loose connection"" between the ring and base of traditional two-piece designs. Ultimately this provides more strength and durability than rival steel rings and bases but doing it with a lighter overall weight. By extruding the billet alloy and then precision CNC machining the mount to its final design, Talley provides you with the strongest, lightest mount system on the market. Scope Tube Diameter – 30mm; Height Options – Low, Medium, High; ABOUT TALLEY - For over forty years, Talley Manufacturing has set a standard for superior quality in the gun industry. Their willingness to adopt cutting-edge technology in our state-of-the-art facility, allows them to continue the quality that the Talley name represents.