The disadvantage of airsoft magazines is that their shell is quite fragile and any fall or impact on them can lead to breakage, not to mention that the interior of mags from most Chinese companies leaves much to be desired.   

To solve this problem, NPO AEG produced stores made from sawn-down original AK-74 mags, the upper part of the mag (the neck) was removed, and the filling was replaced with its own development of the company NPO AEG.   

Thus, you get a reliable internal enclosure with a non-killable and very entourage-like external enclosure. This magazines is the best that can be purchased on the market.