Mark 4 Rings take mounting to an entirely new level. Machined from solid aluminum or steel, this mounting system is one of the strongest available. Designed with long-range shooters in mind, this system will ensure that your scope won't shift under the severe recoil some rifles dish out.Specifications and Features: Country of Origin: United States of America Extended: No Finish: Matte Black Height (Base to Bottom of Tube): 0.453 Inches Height: High Material: Steel Style: Picatinny Tube Diameter: 30mm