Hour Meter: Contains a tachometer, hour meter, and service meter; helps you track the number of hours you spend on the engine. The total hours can be reset; 0.1 hour accuracy The programmable maintenance timer (SERVICE) counts down the maintenance reminder time; when the maintenance time is up, the service warning icon flashes to remind Accurately records engine speed when running to help adjust engine idle speed; can be programmed for different engine ignition modes Replaceable Battery ---- Internal replaceable CR2450 battery, data retention after battery replacement; when the engine stops, the meter will automatically turn off after 2 minutes; press the key to read the screen, data retention after shutdown 1. Applied to all gasoline engines with spark plugs 2. Inductive design, just bundle the connecting wire on the spark plug to work 3. Timing range: 9,999.9 hours; Support speed range: 15,300 rpm 4. LCD display 5. Low voltage design, built-in battery power supply, safe and reliable, battery life is more than 3 years 6. Speed mode can be set, applied to 2-stroke or 4-stroke engines 7. Maintenance time reminder function can be set, and the LCD display will flash to remind when the time is up. 8. System data reset function, can clear all saved dataGood quality product