Vector Optics Tactical Rifle Scope Rings 30mm Tube Picatinny/ Weaver 21.5mm Height 6063-T6 Matte Black. 5mm 0.9" from Bottom to Ring Center Four Screws per Ring Specifications for Vector Optics 30mm Tactical Low Weaver Rings: Manufacturer: Vector Optics Finish: Matte Ring Height: 0.8 in Tube Diameter: 30 mm Ring Quantity: Pair Quantity: 2 Ring Type: Low Fabric/Material: 6061-T6 Aluminum Length: 16 mm Weight: 3.7 oz Color: Black Mount Type: Weaver Gun Rail: Weaver Picatinny Features of Vector Optics 30mm Tactical Low Weaver Rings Easy and quick installation Fit on 21mm picatinny and weaver rail Designed for real firearms With 1 pc torx wrench Package Contents: Vector Optics 30mm Tactical Low Weaver Rings Vector Optics SCTM-27: Tactical Rifle Scope Rings 30mm Tube Picatinny/ Weaver 21.5mm Height 6063-T6 Matte Black