CZ “OEM” mag selections seem to be one of the great mysteries of the universe LOL. I have gone into gun stores several times and sorted through several new gun boxes of the same model and found that they rarely all contain the same exact lineup of included mags. I’ve seen them with the same CZ marked mags, a mix/match of CZ and Mecgar, and even all Mecgar. Even seen same mag bodies but different color followers. They seem to just use whatever they have the most of on hand or whatever they happen to grab off the shelf when shipping LOL. Doesn’t really bother me either way since both mags work just fine for me. When buying extra mags I always buy Mecgar since they are usually cheaper and very good quality. Also I know that CZ-USA has been very agreeable to swapping out mags for customers who aren’t happy about getting a mix & match of mags in an order. Just one of those CZ company idiosyncrasies (there are others too lol) but I have yet to encounter anything that actually affects quality or performance, so doesn’t bother me in the least.