This is a DC power step down converter module that is ultra light weight, just the size of a finger nail.

This  Mini DC-DC Adjustable Step Down Converter is used for DIY mobile power, monitor power supply, buggies power, camera power supply, car power, communications equipment supply.

• Input voltage: 4.5V ~ 28V
  
• Output voltage: 0.8V ~ 20V
  
• Output current: rated current is 2A, maximum 3A (Additional heatsink is required)
  
• Conversion efficiency: 96% (Highest)
  
• Output ripple: < 30mV
  
• Switching frequency: 1.5MHz (Highest) 1MHz (typically)
  
• Work temperature: -45°C to +85°C
  
• Potentiometer adjustment direction: clockwise (decrease), counter clock wise (decrease increase)
  
• Dimension: 22 x 17 x 4mm (L x W x G)