Feature: 1. 1. This relay tester is a quick test tool to test automotive relays and let you know the status of automotive relays. 2. 2. By connecting the car's continuous battery (11V-15V) to the relay coil, the detector can correctly check the contact function of the relay. The tester will observe the contact data, closing time, relay inertia, etc. of each test phase. 3. 3. If the test is qualified, the green light is on, if the test fails, the red light is on. Designed to test the condition of automotive relays. Test to properly control the opening and closing of the relay. 4. 4. The car battery must be a 12V battery, and the voltage must be between 11-15V. The coil resistance is preferably above 20 ohms. 5. 5. A convenient and intuitive diagnosis method is provided, which is time-saving and economical. Small size, compact structure, easy to carry, can be tested anywhere. Specification: Name: Relay TesterColor: black and redMaterial: plastic and metalVoltage: 12VSize: 13x6.8x3cmNet weight: about 180g Package List: 1*Relay tester1*Instruction