NightForce X-Treme Duty 30mm Top Ring Bubble Level This top half of ring replaces the top ring of our 30mm Unimount, Direct Mount, Magmount and Ultralite rings and our 30mm steel rings. Available with integral Angle Degree Indicator mount or as top ring/bubble level only. Available in both four-screw and six-screw versions. The Bubble Level with integral ADI mount (A129) can be turned either way for left- or right-handed actions. NOTE - Clean all mating surfaces thoroughly before mounting; Use a torque wrench and do not exceed recommended torque values: Cap Screws - 25 in lb, MultiMount Rail Screws - 25 in lb. Since 1992, Nightforce has been creating the finest scopes that are used by professionals, hunters, and competitors. NightForce also provides a wide range of high-quality optics accessories