CZ!

[Yournamehere]

Just for your and anyone's benefit, the general rule with mags is buy factory, Mec-Gar, or well noted MilSurp and nothing else. Factory mags can obviously be trusted, as can Mec-Gars since they pretty much make all factory mags anyway, and in some cases you can trust a military surplus mag if it's got a good enough reputation (Airtronics mags for Beretta M9/92 pistols for example). If its a weird mag with no markings that can be discerned, don't risk it, even if it's 10 bucks, just don't risk it and buy some ammo or something.

Additionally, before you go to a local store to buy them, shop around other stores or even online. Sometimes you can get the same things, factory, Mec-Gar or whatever for less than your local dealer is charging, including shipping charges. Online stores like CTD, CDNN, Midway and auction sites like Gunbroker usually have good deals. CZ factory mags look to be relatively expensive and they aren't as common as some other gun mags so it might be harder to find an insane deal, but it's worth a look.