Features :  
Dimensions: 35mmx14mmx10mm
Measurement accuracy: 1%
Refresh rate: about 200mS / times
Display: Three 0.36 "digital tube
Measuring range: DC 3.3V-17V (Can Measure Power Supply 3.3-17V Directly)
Input range: DC 3.3V-17V
Display Color: Blue
Operating current: Less than 20mA
Operating temperature: -10°c  to +65°c
Input impedance: About 100K
Reverse polarity protection: None, please connect Red and Black wire correctly.
Wiring:
Red: Power Supply +, Measure +
Black: Power Supply -, Measure -