Input voltage range : 3-35V DC 

Output voltage range : 3.5-35v DC

Efficiency : 96.7%(max) 

Output current : 6A(max)

Voltmeter range:4 to 40V,error +-0.1v

L * W * H = 6.7 x 4.3 x1.2 cm(approx.) 

When adjust the blue potentiometer ,please use a multimeter to monitor the voltage 

Rotating Clockwise can rise the voltage while rotating  counterclockwise could lower the voltage 

When the module output voltage can not be adjusted ( the output voltage is always equal to the input voltage ) Please adjust the potentiometer counterclockwise 20 laps (20 turns) or more till it works.

The image is for illustration 

1pcs LTC1871 DC DC Step Up Booster Converter + LED Voltmeter  Module