Made by CZ from steel for best accuracy shooting. The ring integrated with base ensures your scope sits as secure and stable as possible, with no compromise. Easy to install and ready to last for a lifetime. All CZ 455s have 11mm dovetails. Beyond that, the dovetails might be 11mm or 3/8 in depending on whether the platform was developed for the US market or the European market. The foolproof way to tell is to take a measurement. 3/8 in dovetails will measure 0.5 in/12.7 mm at the top/widest part of the dovetail. 11mm dovetails will measure 0.433 in/11 mm at the top/widest part. MOUNT 2-part for rimfire rifle and CZ 200 1 in/25.4 mm compatible with CZ 455, CZ 452, CZ 512 and air guns CZ 200.