Input voltage: DC 8V-40V; Output temperature: -10℃~80℃ This voltage thermometer displays red and green light, you can check the voltage and temperature in low light environment. This digital voltmeter thermometer is easy to install and you can install it anywhere you want, such as car interior, desk, workbench, etc. Installing a voltmeter thermometer in the car allows you to monitor the car battery voltage and the temperature inside the car to ensure safe driving. Note: The data are all measured manually, please allow 1-3cm error due to differences in light and display, there may be some color differences, please refer to the actual item received.