This module charges two Li-Ion batteries and can output 3V 1A, or 5V 2.2A! Which is amazing to power most of your circuits, microcontrollers, sensors, etc.
It has two USBs, one to charge the batteries, and the other one is used to charge an external circuit.
The output current of the module depends on the batteries that are used. Do not try to overload the module with heavy loads or it might cause damage to the batteries the module.
Attention: Batteries should be oriented correctly or the module will be damaged. The module is labeled to with the positive and negative terminals of the batteries.