Feature: 1. With LCD display, it can display input and output voltage, output current and output power. 2. The input terminal has anti-reverse protection to prevent the circuit board from being burned. 3. Press the button to control the ON/OFF state of the output terminal, and can set the power-on default to ON or OFF. 4. The anti-backflow designed at the output end does not require additional anti-backflow diodes when charging the battery. 5. Can be boosted and stepped down, the output voltage is adjustable from 0.5-30V,the limiting current is adjustable from 0-4A. Specification: Condition: 100% Brand New Item Type: Step Up Down Module Material: Printed Circuit Board Input Voltage: 5.5-30V (When the input voltage is 5V, it can also achieve step up and down, but the voltage and current measurement is not accurate; when it is lower than 4.7V, undervoltage protection) Output Voltage: 0.5-30V Putput Current: Can work stably at 3A for a long time, and can up to 4A under enhanced heat dissipation Output Power: Natural heat dissipation 35W, enhanced heat dissipation 50W Voltage Display Sub-Rate: 0.05V Current Display Branch Rate: 0.005A Conversion Efficiency: About 88% Soft Start: Support (Very high power load module may fail when starting) Input Reverse Connection Protection: Support Anti-Backflow at Output: Support Short Circuit Protection: Support Working Frequency: 180KHZ. Package List: 1 x Step Up Down Module1 x Heat Sink