Features 1、This boost/buck module can step up or step down voltage and maintain a stable output voltage 2、It supports input over-current protection, input under-voltage protection and MOS input anti-reverse protection 3、It 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 4、Input 5V to 30V and it can charge storage battery, lithium battery, AA rechargeable battery, or adjust constant current LED brightness 5、Red&blue light on when constant current charging, blue light on only when constant voltage charging, blue&green light on when almost fully charged, green light on only when fully charged Specification Description: Features: It supports input over-current protection, input under-voltage protection and MOS input anti-reverse protection. Input 5V to 30V and it can charge storage battery, lithium battery, AA rechargeable battery, or adjust constant current LED brightness. Specifications: Input Voltage: 5V~30V Output Current: 3A (or 4A if enhance heat dissipation) Output Power: 35W (or 60W if enhance heat dissipation) Conversion Efficiency: 87~91%(step up); 87~89%(step down) Input Over-current Protection: 10A fuse Input Anti-reverse Protection: High efficiency MOS Input Under-voltage Protection: Yes Output Over-current Protection: Yes Frequency: 180kHz Size: 69*28*21mm / 2.71*1.1*0.82" Package Includes: 1 x Module Package List