Evolution Gun Works Keystone Series Scope Ring Set 34MM Tube .990in Low Black. One that was versatile robust AND also a great value. We werent happy with the current options on the market so we created our own. Introducing the Keystone Series scope rings. Our rings are measured from where the ring sits on the top of the base to the center of the ring. Our Keystone Series rings are available for 1in 30mm 34mm tube scopes. 1in Tube Heights: .850in LOW .990in MEDIUM 1.275in HIGH 30mm Tube Heights: .850in LOW .990 MEDIUM 1.275in HIGH 34mm Tube Heights: .990in MEDIUM 1.275in HIGH 1.5in EXTRA HIGH If your scope has an objective greater than 50mm or if it has a large power selector knob we recommended .990in rings or higher. One set of rings weighs in at approximately 4.8oz. We recommend that you torque the crossbolts of our Keystone Rings to 65 inch pounds and the top screws to 15 inch pounds. Specifications for Evolution Gun Works Keystone Series Scope Ring Set: Manufacturer: Evolution Gun Works Finish: Matte Black Anodized Quantity: 1 Fabric/Material: 6061 Aluminum Color: Matte Black Mount Type: Weaver Features of Evolution Gun Works Keystone Series Scope Ring Set Machined in house in one of our CNC machining centers 6061 aircraft grade aluminum T15 mounting hardware for the ring caps Chromoly crossbolt and ? nut for reliable and repeatable engagement Fits picatinny and weaver style rails Horizontally split design allows for easy installation Package Contents: Evolution Gun Works Keystone Series Scope Ring Set Evolution Gun Works 62200: Keystone Series Scope Ring Set 34MM Tube .990in Low Black