First off. Holy. Freakin'. Crap. These mags are AMAZING. They're tough as hell. They have a polymer outer shell and a high strength ABS inside that you can take apart if something goes wrong. The inside spring compartment consists of a winding spring in a sideways S pattern that consists of two pieces that push the bbs throughout the mag and up into your M4/M16. One piece sits on top of the spring while the other is a slightly curved oblong shaped plastic piece that helps the bbs around the curves of the mag. I've THROWN this mag at the concrete HARD. To test it's durability. It still fed like a champ without a scratch.
Multiple internal pieces to ensure fast feeding
Overall spectacular design
Does not come with sammiches
Doesn't include gold bullion
Rating: [5 of 5 Stars!]