It is Mobile power bank Battery Charge, Discharge, Protection & Boost Circuit board module.

You can make your own power bank using this module. It can charge up to 4 batteries in parallel.

The module comes with protection function, Overcharge protection, Over-discharge protection, Overcurrent protection.

Intelligent Overcharge protection system automatically stops charging once the connected device is fully charged. Stable Output voltage and current

Input Micro USB: 5V 1A

USB Output: 5V 1A

Batteries Type: Lithium-ion batteries

Battery Quantity: Can operate up to 4 batteries in parallel