Burris Signature 30mm Medium Rifle Rings - Matte Black - Machined from a solid piece of steel, the 30mm Signature Medium Dovetail Rings for Mounting Riflescopes from Burris Optics offer precision, strength, and durability. They hold you scope at 0.78in (19.8 mm) height and feature a Medium Dovetail style adapter and 30 mm riflescope main tube compatibility. These rings also include Pos-Align inserts that improve centering and maximize scope-to-ring contact. This improved gripping power without damaging your scope's finish.