About this item 30mm scope rings fit 20mm dovetail mounts,rails and bases Quick release scope rings fits standard 20mm Weaver / Picatinny rail, aluminium alloy construction with a matte black finish Scope ring with quick detach/lock lever with full adjustability to fit on any picatinny rail High profile scope rings (item height:2.48″/63mm),the height from the center of the riflescope tube to the picatinny base is 1.57inches(40mm) Medium profile scope rings(item height:2.36″/60mm),the height from the center of the riflescope tube to the picatinny base is 1.45inches(37mm)