Features: ①Spark plug performance test; ②Standard comparison test; ③Simulate engine operating conditions; ④Wide working frequency range; ⑤LCD display; ⑥ Plug and play; Product parameters: Working frequency up to 9000 rpm Input power: AC110V / 220V ± 10% 50H z/60Hz Output power: DC12V ± 2 1A Analog revolutions: 0~9999 revolutions/min Ambient temperature: 0°C~+45°C Relative humidity: <85% Host size: 192mm X 115mm x 53mm / 7.6 X 4.5 X 2.1inch Weight: 1.1KG / 2.425 pounds Safety Warning: 1.Do not pull out or insert the spark plug with the power supply connected If you want to insert or pull it out please turn off the power first 2.When the spark plug is running, the voltage can reach tens of thousands of volts, so don't touch it directly with your bare hands to avoid injury.