Specifications:

• IC Chip:MP1584EN.
  
• Input Voltage:4.5V-28V.
  
• Output Voltage:0.8V-20V.
• Output Current: 3A Max
  
• Output Ripple:Less than 30mV
  
• Conversion efficiency: 92% (highest)
  
• Switch frequency:1.5 MHz (highest),typical 1 MHz
  
• Dimension:22mm * 17mm * 4mm.
  
• Operating Temperature: -45°C ~ + 85°C

You can adjust the voltage by placing a multimeter synchronously at the output, and adjust the potentiometer with a screwdriver. It can achieve precise voltages with tiny adjustments.
Do not short-circuit the output.
When setting parameters, ensure that the output voltage is stable before using the module.

NOTE:
Pay attention to the positive and negative poles;
If used at large current for a long time,heat dissipation is recommended;
Do not use light load(less than 10% of the output power) or no-load;
If the output voltage is always equal to the input voltage,turn the potentiometer clockwise for more than 10 turns.