USMC Molle Hydration Combat Carrier Vest Black
[AS928]

Fits perfectly and it's very comfortable. The built-in magazine pouches can fit two m4 mags and can even be adjusted to fit other kinds of mags, not only m4/m16 as it says. The best thing about this vest is that it hangs low thus keeping sweat to a minimum while playing while still having all your gear available.