For the money, I'd rather get the Elite Force polymer mags. I found these to be a little fragile and I've had two lose the rubber o-ring within the first week of using them. I've had better like with the Elite Force mags. Also, loading these mags was a bit of a pain compared to other similarly priced mid caps.
Work well when they don't break
Stubborn to load
Not a high quality build
Rating: [3 of 5 Stars!]