If you have a CZ452, most likely it has "11mm" dovetails - measure the width of the grooves on top of your receiver at their widest point. My CZ 452 Silhouette measures 11mm; my CZ 452 Scout does as well. European 11mm dovetails measure 11 mm (0.430") right there. North American makers use "3/8" dovetails and have a 45 degree angle, not a 60 degree angle like Europeans do. As a result, North American "3/8" dovetails (they measure width across the bottom of the cuts) will measure pretty close to 0.5" at their widest edge near the top. Over various years, CZ made both widths on various models, so worth your while to check what you have, before ordering anything. A scope needs rings - you need rings to match your dovetail and your scope body size, unless you are going to have rifle drilled and tapped, then can do most anything that you want.