SMAKN&reg; 5pcs Mini MP1584EN Step-down Power DC-DC 3A Ultra Adjustable LM2596 Step-down Module This is a tiny, powerful step-down (Buck) switching voltage converter with a wide operating range. The output is set with a potentiometer. Input Voltage: 4.5V-28V. Output Voltage:0.8V-20V. Dimensions:22mm * 17mm * 4mm.