Features: This is a great DC to DC step-up power supply module for electric equipment, digital products, etc. Input and output are designed with screw terminals for convenient wire connection and disconnection. There is a heat sink on board that would make sure a better heat dissipation. Designed with USB and 2.5A large current output, can identify resistance and charge several phones at same time. It can also be used as a power supply for laptops or voltage regulator for solar panels. Specifications: Input Voltage: 4V-35V Output Voltage: 5V-45V Input Current: 5A(Peak) Voltage Display Range: 5V-30V(if input voltage is lower than 4.5V, it will not display) Voltage Display Error: +/-0.1V Size: 72*48*16mm / 2.83*1.89*0.63" Note: 1, This is a boost module so output voltage should be higher than input voltage. 2, Peak output current is less than 5A. 3, This kit requires professional knowledge and ability, please make sure you know how to use it. Instruction: 1. Connect the module to power supply (4-35V), the input indicator light is on, and module is working normally. 2. Adjust the blue potentiometer knob (generally turn clockwise to step up and turn counterclockwise to step down) and check the output voltage with a multimeter until it meets requirement. 3.If the output voltage of the module can not be adjusted, which means it is equal to the input voltage, please turn the potentiometer counter-clockwise for several circles then the voltage can be adjusted normally. Package Includes: 1 x Boost Module