Specifications: 4 mini voltage testers (blue, red, green, yellow) Measurement range: DC2. 4-30V High Quality: Stable performance and high precision. When the voltage is less than 10 V, the resolution is 0.01 V. The voltage resolution above 10 V is 0.1 V. This ensures both measurement accuracy and higher voltage. Practical and easy to assemble: small and light. Reverse polarity protection and 2-wire digital voltmeter for easy installation and connection. Guarantee: We trust our voltage testers. Let every buyer have a satisfying and pleasant shopping experience here. Product Description Product Features: There are 4 colors of lights to display the measurement results: blue, yellow, red, green. Automatic precision adjustment. When the voltage is less than 10V, the resolution is 0.01V. The resolution of voltage above 10V is 0.1V. Detection voltage: DC 2.4 V - 30 V Dimensions: 30 11.5 9 mm (length x width x height) Mounting holes: 23 10 mm Operating temperature: -10 - +65C Operating humidity: 10 - 80% p> Operating pressure: 80 - 106 kpa Packaging Contains: 4 mini digital voltmeters (red, yellow, green, blue)