what brand is your g36? This actually is important and I forgot to ask and not sure if it was answered or not...
ares g36s like ares mags... I've spoken to a few owners that say other mags tend not to stay in the magwell or fit well. We know that g36 pmags fit nicely though, we tried some of my mags in some ares guns. non ares mags were reported to be loose in ares guns.
If you have a non ares g36, it might be better to get any other brand of magazine, since the fit might be that much different. It could be that they will fit too tight, or they are shaped slightly different and might not feed well.
Also.. don't order from evike. Aside from screwing up the order, they will charge you ridiculous amounts to ship your product. There are far more reputable local canadian dealers that sell condor gear that I would much rather give money to, even if the prices are a bit higher.
The are also better US condor dealers than evike.