This is the MT3608. It is a exact copy of the famus MT3608 board. It is a DC-DC step up adjustable boost converter. It can take input voltages as low as 2V and step up the output to as high as 28V. The MT3608 features automatic shifting to pulse frequency modulation mode at light loads. It includes under-voltage lockout, current limiting, and thermal overload protection. This module has a multiturn trimpot (potentiometer) that you can use to adjust the output voltage. Since the trimpot has 25 turns of adjustment you can easily adjust the output of the module to exactly the voltage you need. Boost converters are a great way to easily increase a given voltage, but that boost comes at the cost of less output current compared to input current. Since this is a boost converter the output voltage has to be higher than the supplied input voltage. I hope you have fun with it! ;)