Feature: 1. The dual‑hole spark plug detector has two testing holes, which can detect two spark plugs at the same time. 2. If the spark plug is found to be working improperly, a comparative test can be conducted to make an accurate judgment. 3. Application range of ignition plug analyzer is 12V gasoline vehicles car spark plugs. 4. The main function of the adjustable two‑hole automotive spark plug detector is to test spark plug performance and ignition intensity. 5. With elaborate manufacturing technology, has high reliability and stable performance. Specification: Item Type: Spark Plug Tester Material: PlasticPlug Type: AU Plug Wide Voltage 100-240V Car Spark Plug Test Principle: In automobile ignition system, the high-voltage ignition coil generates a high-voltage (10000 volts or more), and the spark plug diverts it form high -tension ignition coil into the cylinder engine, spark between the spark plug electrodes will ignite the mixture. The Detector could tell the good spark plugs from the bad by the strength of the spark. Power Adapter: Input 100-240VAC / Output 12V 1A DC Application Range: 12V Gasoline vehicles car spark plugs. Package List: 1 x Spark Plug Tester1 x Power Supply Device1 x Manual Note: 1. Turn off the power before placing the spark plug 2. The spark plug tester is a high pressure detector, do not touch the spark plug when working, in order to avoid danger.