Qunqi LM2596 Buck Converter 4.0~40 to 1.3-37V Adjustable Step-Down Power Module with LED Display Voltmeter Led Digital Voltmeter Tube, The Accuracy Is Adjustable Function, Can Be Aimed At Your Multimeter Adjustable Accurate. Input voltage range: 4~40V DC Adjustable output voltage range: 1.25~37V DC Output current: 2A(for stable operation) Max output current: 3A Volt meter range: 0 to 40V Volt meter accuracy: 0.1V Internal oscillation frequency: 150KHz Some customers report: &#034;The module can not be adjusted, the output voltage is always equal to the input voltage.&#034; When you encounter this problem, please counterclockwise rotation of the potentiometer 10 laps or more, then you can adjust the output voltage. Because the factory default output voltage is 20V