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