G&P Gen II Spare Magazine for WA G&P King Arms M4 Series Airsoft Gas Blowback

"So I bought 5 of these in one purchase and they all came very well lubricated. The only issue was out of the box 3 of them came extremely leaky. The other 2 worked fine until one of the two bit the dust about 2 months later. Now I don't know if I got a basket full of lemons but either way I am a little annoyed that I have wasted roughly 160 dollars. But, the one mag that has not broken works fantastic. The mag has quite a large gas reservoir which can allow me to 2 full mags on semi. The mag also has a decent cooldown time and does not freeze up often. Overall, please with the one mag, incredibly disappointed with the other 4.