This dual magazine is AWESOME! When mine arrived, there was a broken wire inside. Being a tinkerer, I didn't get PO'd, I took it apart an made a simple repair. J. Martin's comment about a screw-head broken off isn't quite right. The flathead screw in the center is actually a long screw holding the halves together. Where the screw appears broken off on the front it is really a threaded insert. I am thinking about putting a short screw there on the available threads just so it doesn't LOOK like a broken screw.
I have used mine for a couple of weeks now on a JG M4 Enhanced S-System, and it works great! When I first used it I had a few misfires, but I sprayed a little silicone lube down the feed-tube and it works fine with no misfires.
I think the dummy bullets look good enough.
Very high ammo capacity.
Looks very impressive.
Feeds well (use a little silicone).
Easy to use and insert into the receiver (on my gun at least).
Battery charge lasts a LONG time.
Received with a broken wire (no biggie to me)
Rating: [5 of 5 Stars!]