Manufactured By Atomic Market 
This is a tiny, powerful step-down (Buck) switching voltage converter with a wide operating range. 
This device is about the size of a US Quarter. 
The output is set with a potentiometer. 
Package Contents 

1 Buck Converter Voltage Regulator 
Specifications 

IC Chip: Monolithic Power Systems (MPS) MP1584EN 
Input Voltage: 4.5V to 28V 
Output Voltage:0.8V to 20V 
Output Current: 1.8 A typical (3.0 Max) 
Output Ripple Frequency: 340 KHz 
Ripple Voltage: 30mV 
Output Accuracy: +/- 0.5% 
Dimensions: 1.7 x 1.7 x 0.4 cm 
Operating Temperature: -50 ~ +85 deg. C