Fangrui Product Details This Is A Great 400w Dc To Dc Step-up Power Supply Module For Electric Equipment, Digital Products, Laptop, Etc. Input And Output Are Designed With Screw Terminals For Convenient Wire Connection And Disconnection. High Efficiency, The Maximum Conversion Efficiency Can Be And Efficiency Is Related To Input/output Voltage, Current And Voltage Difference. There Are 2 Heat Sinks That Would Ensure A Better Heat Dissipation. It Can Also Be Used As A Driver For High Power Led Lights Or Voltage Regulator For Solar Panels. Output Voltage/current Adjustment: 1, Adjust Cv-adj Potentiometer Clockwise To Reduce Voltage, Counterclockwise To Increase Voltage. 2, Adjust Cc-adj Potentiometer Counterclockwise About 30 Circles To Minimize The Output Current Before Connecting To Load(clockwise To Increase Current, Counterclockwise To Reduce Current). Then Adjust Cc-adj Clockwise To The Current Value You Need. If You Use The Module For Battery Charging, Connect To Output After Battery Is Fully Discharged. Because If The