The DC-DC Step-down Adjustable Power Supply Module with 3digit LED Display is based on monolithic integrated circuit LM2596, ideally suited for easy and convenient design of a step−down switching regulator (buck converter). It is capable of driving a 3.0A load with excellent line and load regulation. This device is available in adjustable output version and it is internally compensated to minimize the number of external components to simplify the power supply design.
Easy to connecting of power wires. PowerIn to green terminal block, PowerOut to blue.

This module has 3 digit voltmeter  display on board. With the button you can change the display voltmeter information to input or to output.