New XTR Signature Rings were designed for the tactical shooter. They deliver plenty of holding power with less weight. Each ring set includes one set of the +/- 0 MOA concentric, one set each of the +/-5 MOA and +/-10 MOA, and two sets of the +/-20 MOA. With these inserts, it is possible to make 0, 5, 10, 15, 20, 25, 30 or 40 MOA of cant in the scope mount. Features: Corrects misalignment caused by off-center receiver holes No need for expensive tapered bases or shimming for thousand-yard shooting