May require some minor fitting, please check there is a light gap under the sight blade after fitting. If the rib is touching the underside of the sight it can put pressure on the sight blade and cause breakage. Notch is .125 wide X .096 deep. CZ Custom Competition Rear Sight (in our testing we have found that). CZ 75 85 all Standard Dovetail Cuts. Will require 6.5mm Front Sight. CZ 97B all Standard Dovetail Cuts. Will require 5.5mm Front Sight.