DC-DC Boost Module Voltage Digital Display LM2577 Boost Circuit Board 3A Output 1. Equipped with a voltmeter display, with an error of 0.1V and a range of 0-40V. (Note: To the accuracy of the voltmeter, please that the input voltage is above 3V) 2. Lightly touch the button to switch between measuring input or output voltage, and there is an indicator light showing which one is being measured Road voltage; 3. It has a power-off memory function and displays the last measured voltage value when powered on; 4. Long and lightly touch the button for 3 seconds to turn off the LED display, and lightly touch the button again to turn on the LED display Show; 5. With wiring terminals, it can be easily used without a soldering iron, and the connection points are retained; The output current can reach up to 2.5A; Color: As Shown Material: PCB Package Contents: 5 x Step-Up Module Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.