buy poweradd portable power bank amazon you are right,the price low htan other,and quality the same,anker 5200mAh power bank sale with 19.99$,but we only 12.99$,the same size,same color,one use port and LED Flashlight,our reviews is 4.2,anker is 4.3.why the same quality you dont't buy the cheap,maybe you don't konw ever,now tell you friend now,before buy you can compare with more than three seller.frome there price,quality,reviews,and exterior,have a good time.rick!