CZ Direct fit upgrade Designed to fit the 19mm 550 integral dovetails, Warne's Maxima CZ rings are a solid steel, vertically split ring that handle even the most punishing recoil, or large, heavy scopes. Since each firearm manufacturer has their own proprietary mounting rail design, each ring model must be machined to exacting tolerances for proper fit and function. Because of this, the Warne CZ Rings are able to fit right onto the receiver's dovetail with no need for a mounting base. The CZ Fixed Rings fit the CZ550 receiver design (19mm dovetail) model and utilize 4 T-15 Torx style socket cap screws for secure and permanent optics mounting.