This tester is designed to test the condition of your car relay to properly control the opening and closing of the relay.If the relay is abnormal, the red LED will light, and it& 39;s normal, the green LED will light.Car relay tester provides a convenient and intuitive diagnostic way, which is time-saving and economical.The auto diagnostic repair tool is portable, small, and compact structure, you can test anywhere you want.The car battery must be a 12V battery, the voltage must be between 11-15V, the coil resistance is preferably at least 20 ohms.Specification:Material: Plastic+Metal.Color: Black Red.Size: 13x7x3cm.Voltage: 12V.Note:There might be a few color distortions due to different computer resolutions.There might be slight errors due to different hand measurements.Package Included:1 x Car Relay Tester.