The Rimfire rings are designed to fit a very wide selection of rifles with either a 3/8" or 11mm dovetail. This is made possible by using a solid asymmetrical reversible clamp that can be flipped 180 degree and used on wider or narrower dovetails for the best fit. Features: - all steel rings with a horizontally split design and only 1/2" wide - assymetrical reversible side clamp fits a 3/8or 11mm dovetail - securely mounts to firearm with torx style T-15 socket cap screws, 25 in/lb. Of torque recommended specifications: - style: Rimfire - height: high - tube diameter: 1" - extended: no - material: steel - height (base to bottom of tube): 0.525" - finish: matte black..