1. 4X18650 2600mAh quality batteries,
2. reliable PCB board design, at least last for 5 years,
3. shipping 300000 PCS monthly in domestic China market,
4. two USB power output for 1A and 2A (for tablets or quicker charging),
5. compact design, one hand can held your phone and this external battery together,
6. graceful housing design like an art work.