MecGar makes the factory mags for CZ for both the Shadow and the Shadow 2. If you're seeing those crap 1/3 plastic mags still, they are old old stock that should just be tossed out. The MecGar mags are superior in every way to those old mags, which is why CZ went with them a few years back for the Shadow 2 and Shadow.
Do not buy the Tanfo mags, get the MecGar ones for CZ, if you're a lefty you can't swap your mag catch and have it work with the Tanfos, and, the mag catch slots aren't in the exact same place for right handed shooters either, which can lead to issues with the mag being over inserted and hitting the ejector, causing it break if it happens enough.