Do yourself a favor and get it - Anarchy Outdoors Extended Mag Release Gen 2, CZ Rimfire

If you've ever used a CZ 457 you know the mag release lever is absolutely tiny. While it works fine, it is very difficult to use without feeling around for it. If you are only going to use 5 round magazines it's probably nice to have because it sits so flush. However, if you're like most CZ owners you'll be using mostly 10rd or larger magazines 99% of the time. This mag release lever makes it way easier to drop your mag and even acts as a bit of an index point for loading a fresh magazine.