Features This module can be applied to the buck field where the input voltage is higher than the output voltage, such as battery, power transformer, DIY adjustable power supply, industrial equipment step‑down. With power indicator, 5A high power high efficiency step‑down low ripple. With heat sink and standoff for overheat protection and short circuit protection. With voltmeter display and the voltmeter can be self-calibrating. Using a more advanced voltage microprocessor, voltmeter error ± 0.05V, range 0 ~ 40V. Specification:Item Type: XL4015 ModuleInput Voltage: 4.0~38V (the input voltage must be 1.5V higher than the output voltage) Adjustable Output Voltage Range: 1.25V ~ 35V, Continuously Adjustable (input voltage must be 1.5V higher than the output voltage) Output Current: Up to 5A, recommended for use within 4.5A Output Power: Up to 75W High Conversion Efficiency: Up to 96% (efficiency related to input, output voltage, current, voltage difference) Load Regulation Rate: S(I)≤0.8% Voltage Regulation: S(u) ≤ 0.8%Onboard Voltmeter Self-Calibration Method: 1. When the on-board voltmeter shows the output voltage, press and hold the right button for 2 seconds and then release it. The voltmeter and output voltage indicator “OUT” flash synchronously. At this time, the output voltage adjustment mode is entered. Similarly, the voltmeter displays. When inputting the voltage, long press the right button for 2 seconds and then release, the voltmeter and the input voltage indicator “IN” flash synchronously, then enter the input voltage adjustment mode Package List:1 x Module4 x Standoff4 x Nuts1 x Heat sink Note:The module output voltage cannot be adjusted and is always equal to the input voltage. When you have this problem, please turn the potentiometer counterclockwise for more than 10 turns, then use the module to adjust the voltage normally. Because the default output voltage of set down module is about 20V. Package List 1 x Module 4 x Standoff 4 x Nuts 1 x Heat sink