Relay tester that provides you with an indication of the general condition and operation of the most common automotive relays. Small size and compact structure, easy to carry and use. You can test anywhere as you wish. The car battery must be 12V, the voltage should be between 11 and 15V. The coil resistance is preferably at least 20 ohms. If the relay is abnormal, the red LED will light up; it is normal for the green LED to light up. The tester observes the contact data, closing time, relay inertia at each test step, etc. Quick and easy car relay test, provides a convenient and intuitive way of diagnosis. Voltage: 12V. Material: Plastic and metal. Color: Black & Red Item Size: 12 x 6 x 2.5 cm. Features: It is a quick test tool for testing automotive relays, so that you know the status of automotive relays. Through the continuous automotive battery (11V-15V) to the relay coil, the detector can correctly check the relay contact function. The tester observes the contact data, closing