||Overall, this is a pretty good mag by Guarder. It can be very hard to find M4/M16 mags in a chrome finish (belive me I've tried). My friend got this for his JG M4 S-System, and I am considering getting this mag when I get my JG M4A1.
Lightweight (doesn't add any weight to the gun which is great)
Extremely hard to find
Usually very expensive (evike took care of that though)
Will jam if you shoot on full auto for long periods (easy but time-consuming fix just take out the gears and hit them with an allen-wrench the BBs come right out)
Overall, another quality product by Guarder
Rating: [4 of 5 Stars!]