Ruff's Precision Manufacturing Precision Co-Linear Bubble Level 35mm Riflescope Ring High - 1.25'' Set of 2 Black. 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 of the rifle during the scope mounting process while eliminating the need for multiple small levels and balancing acts Specifications for Ruff's Precision Manufacturing Precision Co-Linear Bubble Level 35mm Riflescope Ring: Manufacturer: Ruff's Precision Manufacturing Base/Mount Type: Riflescope Ring Tube Diameter: 35 mm Ring Quantity: Pair Ring Type: Rings Fabric/Material: 6061-T6 Aluminum Color: Black Features of Ruff's Precision Manufacturing Precision Co-Linear Bubble Level 35mm Riflescope Ring 6061-T6 aluminum ring body and cap 303 stainless steel cross bolt and nut (1/2'') Alignment lug to ensure cap/base alignment during cap screw installation Package Contents: Ruff's Precision Manufacturing Precision Co-Linear Bubble Level 35mm Riflescope Ring Ruff's Precision Manufacturing CLR-35125: Precision Co-Linear Bubble Level 35mm Riflescope Ring High - 1.25'' Set of 2 Black