Talley makes a nice ring as well that fits perfectly. CZ dovetails can sometimes be a challenge to fit rings to, as they have different angles than North American 3/8" dovetails. The best bet is to measure first, then order or buy rings. I'm using both Leupold and Talley rings on CZ rimfires. The Talleys fit deeper into the dovetail, but the Leupolds work for me, but some say they have had canted rings as a result of insufficient engagement of the rings into the dovetail. Talleys cost twice as much though.