PEMENOL DC to DC Output Adjustable Voltage Converter 5V to 33V 9V 12V 18V 24V Step Up Down Module Buck Boost USB Power Supply Module

Key Function: “ON”: Short press – controls whether the output is turned on or off, and is used to reduce the voltage or current value when in the calibration mode.             Long press - long press for more than 3s, the digital tube is closed, press any key to restore the display. "SW": Short press - switch between voltage, current, and turns display, when used in calibration mode to increase voltage or current values.             Long press - enter or exit calibration mode (enter calibration voltage mode when voltage is displayed, enter calibration current mode when current is displayed)