It seems that once again, KWA has utterly failed... At making anything less than perfect. This is the single best magazine I've ever used (Runner up is A.E., but they don't fit my KWA KM4A1). It never misfeeds, it fits snugly into the mag well, and it looks damn cool. My only complaint is that KWA doesn't make a 450 round hi-cap.
Easy and quick winding
Fits securely, but falls right out when released
not all that expensive
Honestly, there are no cons that I can point out.
Rating: [5 of 5 Stars!]