Matrix M4 Magazine 18650 Battery Power Bank & Charger (Color: Black / Case Only)

"Pretty nifty device. Its good for 2 full charges to my iphone 16 on a full battery. Up to 5 rounds of 556 or 223 actually fit in the mag, however the mag will not fit in an ar15 or m4 for that matter. The top of the mag is slightly too big but cant tell the difference