Specifications:
Measuring range: three-wire DC 0~100V
Working voltage: 4~40V (with reverse connection protection), higher than 40V may be damaged
Test accuracy: ±1% >10V error positive and negative 0.2V <10V positive and negative 0.03V
Input impedance: 50KΩ
Working current: <30mA
Refresh rate: about 100mS once
Display specifications: three wire 0.28' LED digital tube
Lead length: default 15cm
Shape ruler: 33 x 11.5 x 9 mm
Mounting hole: 23*10 mm
Opening size: hole distance: 26mm hole diameter: 2.2mm
Working temperature: -10 ~ +65 °C
Working humidity: 10 ~ 80%
Working pressure: 80 ~ 106kPa
LED Color:Red/Blue/Green

Features:
• 2 Connection Methods:3 wires are connected separately to measure voltage and power(yellow red is both forpos, black isneg); 3 wires are used as 2 wires, connected to measure voltage and Yellow can be pair forpos, black isneg).
• Mini Voltmeters:Total 4PCS, 4 colors optional each one; 0.28 inch LED Panel; small in size and light in weight.
• Features:Reverse polarity-protection, voltmeter will not burn out if reverse-polarity is applied; high-precision; low starting working voltage; fine adjustment function.
• Good quality: This product is made of high-quality materials, exquisite workmanship, very good quality and long service life.

Package include:
4x 0.28inch Digital Mini Digital Voltmeters