This is a Warne Scope Mounts Ring known as the Fixed, model 1BM.
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.
Features:
CZ specific recoil pin for positive engagement of ring to receiver dovetail
Uses 4 Torx style T-15 socket cap screws 25 in/lb. of torque.
