Feature: 1. [Spark Plug Tester] With strong ignition performance, the working frequency is 200 to 9000rpm, can be adjusted through button. The higher the frequency, the better the spark strength. With protective cover to prevent electric shock. 2. [Three Hole Testing] The spark plug tester can simulate the working conditions of the engine realistically, with three holes that can compare three spark plugs simultaneously to improve efficiency. 3. [Plug and Play] Simply place the spark plug to be tested into the test hole, cover with protective cover, and then connect the power supply to start the test. With digital screen displaying working speed for precise control. 4. [Premium Material] The car ignition plug detector is made of premium ABS, which is sturdy, resistant to heat and impact, ensuring long service life. 5. [Widely Used] Compatible with 12mm diameter 12V gasoline vehicles, compatible with 99% of crank engines and motorcycle spark plugs on the market. Specification: Item Type: Spark Plug Tester Material: ABS Model: CNBJ-920 Host Size: Approx. 135x125x120mm / 5.31x4.92x4.72in Display: LED Screen Backlit: Blue Rotation Speed Range: 200-9000RPM Input: 1. Power Adapter 2. DC Cable (DC12V) Relative Humidity: ≤85% Operating Conditions: -10℃~45℃ Storage Conditions: -20℃~50℃. Package List: 1 x Spark Plug Tester 1 x Supply Adapter 2 x Supply Clips 1 x User Manual