DC-DC USB Step Up & Step Down Adjustable Converter Module

From the shop's description

USB boost/buck power supply module, powered by USB, adjust potentiometer to get the required voltage. Features: One button to turn off the output. Supply ON/OFF display screen. Support low power mode. Support sleep mode. Support both standard USB and Micro USB and pads input voltage. Potentiometer with rotating handle. Parameters: Input voltage: DC 3.5-12V. Output voltage: DC 1.2-20V. Output power: Input 1.2-2V, output power within 2W. Input 2V-20V, output power within 3W. Input 20V-24V, output power within 2.5W. Display: 3Bit digital tube display. Size: 80x22x14mm. Using Steps: Input voltage from Standard USB or Micro USB or ‘VIN+’ and ‘VIN-’ Turn ON display screen. Adjust potentiometer to get the required voltage. Connect load. Application: Ordinary power supply Battery charger LED drive power Instrument voltage display Test meter Circuit test Power conversion