Features: Widely application. Wide voltage work, red minimum measured voltage 2.5V, maximum safe pressure up to 30V, more than 30V May be damaged. Conventional without external working power- supply, can use the measurement voltage directly work, measurement voltage ranges two-line 2.5-32V. When measuring the voltage below-10V, two digits- are displayed after the decimal-point; When measuring voltage above 10V-, one digit- is displayed after the decimal-point. The voltmeter connection is simple, conventional use of two wires, red connection positive, black connection- negative, there is reverse connection protection, reverse connection is not burning. Specifications: Material: ABS- Measurement Ranges: 2.5-30V Refresh-Speed: 100mS Once Default- Lead Length: Apporx. 15cm Working Humidity: 10-80% Working Pressure: 80-106kPa Working Temperature: -10 to 65 Size: Approx. 30x11.5x9mm/1.18x0.45x0.35in Mounting Hole: Approx. 23x10mm/0.91x0.39in Color: Red/Green/Blue/Yellow Note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1x Voltmeter