The Warne Maxima Vertical PA scope rings is designed to fit the 16 mm 527 integral dovetail and constructed of a solid steel vertically split ring that handle recoil or large, heavy scopes. Being that each ring model must be machined to exacting tolerances for the proper fit and function, the Warne CZ Rings are able to fit onto the receiver's dovetail with no need for a mounting base. The CZ Fixed Rings utilize 4 T-15 Torx style socket cap screws for secure and permanent optics mounting.