Check the listing for details. LM2596 DC 4.0-40 to 1.3-37V Adjustable Step-Down Buck Power Module + Voltmeter. Condition: New. Listed at 6.89 USD. LM2596 DC-DC 4V - 40V in / 1.3V to 37V Out 3A Buck Step Down Voltage Converter / Regulator Module with LED Input/Output Voltmeter Display Features: Switchable LED display shows both input voltage and output voltage, eliminates the need to hook up a DMM / multimeter to measure the input and output voltages. Analog Control: Use a mini screwdriver to increase or decrease output voltage by adjusting the potentiometer screw, clockwise to increase voltage and counterclockwise to decrease voltage.Has very stable output, input range is DC 4~40V and output range is DC 1.3V to 37V, The input voltage should be higher than the output voltage by at least 1.5V. Press the button to the right of the voltmeter to display input voltage or output voltage. "OUT" LED lights on when the output voltage is displayed, tap the button and "IN" LED lights when the input voltage is displayed. Display On/Off button to the left of the voltmeter turns off the display.Screw-type wiring terminals require no soldering, input and output wires can be attached with a screwdriver. Solder pads are also provided for permanent connection. Specifications:DC-DC Buck Converter Step Down Module LM2596 Power SupplyInput Voltage: DC 4V - 40V (the input voltage should be higher than output voltage at least 1.5V) Output Voltage: DC 1.3V - 37V (continuously adjustable) Output Current: 2A continuous, 3A peakOutput Power: 15W continuous maximum LED Voltmeter: 0~40V Voltmeter Accuracy: .+/-0.1V Internal Oscillation Frequency: 150KHzOutput ripple: 30mA maxmumSize: 66mm x 35mm x 14mm (2.6 inches x 1.4 inches x 0.55 inches) There is a large area of copper on the back of the circuit board to enhance heat dissipation Package Includes:1X DC-DC Buck Converter Step Down Module LM2596 Power Supply with LED input/output voltage displayLink to online installation and operation instructions Get it faster! Stocks and ships from our Colorado office for quick US delivery. We provide FREE USPS First Class Shipping with Tracking - Not Slow Economy Shipping