1This boost/buck module can step up or step down voltage and maintain a stable output voltage 2It supports output voltage stability function, voltage regulation function and under-voltage protection 3With high conversion efficiency and high power, it has better performance and is very convenient to use 4It has quite low output ripple voltage, for example, 20mV when output is 12V 3A, which is great for powering speaker, audio amplifier, artificial circuit, etc 5This module can be powered by phone charger or battery, and output adjustable 0.5V to 30V DC power