Modulo Power Bank Step Up 5v 1a Diy Itytarg

Description:
 
Motherboard size: 72 * 18 * 51mm
Capacity: 10400mAh
Material: aluminum alloy
Surface treatment: oxidation (frosted surface)
4 power indicator: 25%, 50%, 75%, 100%
input: 5V / 1A output: 5V / 2.1A
To adapt to any voltage in 3.2-4.2V flat head 18650 battery or polymer rechargeable lithium battery
(Note: B + for the positive pole B- for the negative, can not be reversed)
Can use 4 or 8 batteries connected in parallel