To Test spark plugs performance and ignition strength, apply to 12.0V gasoline vehicles car spark plugss. Features: Dual hole car spark plugs tester detector have two testing holes, you can test two spark plugss meanwhile and and if you suspect any spark plugs works improperly you could compare and test to make accurate judgment. The Detector could tell the fine spark plugss from the bad by the strength of the spark. Accurately test the spark plugs performance and ignition strength. Application Range: 12.0V gasoline vehicles car spark plugss. Plug and play, convenient and easy to use. Specifications: Material:Plastic Color: black Item size: 140 * 77 * 38mm / 5.5 * 3.0 * 1.5in Item weight: 335g / 11.8ounce Package size: 170 * 130 * 60mm / 6.7 * 5.1 * 2.4in Package weight: 380g / 13.4ounce Packing List: 1 * spark plugs Tester 1 * Power Adapter