30mm precision scope ring set with built in co-linear bubble level.Built in level is visible from the shooting position with the shooters' non-dominant eye for quick reference prior to the shot.Level significantly aids in accurate scope mounting by giving reference to the cant during the scope mounting process while eliminating the need for multiple small levels and balancing acts! 6061-T6 aluminum ring body and cap303 stainless steel cross bolt & nut (1/2")Alignment lug to ensure cap/base alignment during cap screw installationProudly made in the USARecommended torque values:Cap screws: 18in/lbs Cross bolt: 45in/lbsWeights: CLR-30885: 3.9ozCLR-30100: 4.4ozCLR-30125: 5.0oz