Hour meter：Contains tachometer, hour meter, service meters; helps you track how many hours you have spent on your engine. The total number of hours can be reset; 0.1 hour accuracy. MAINTENANCE REMINDER：Programmable maintenance timer (SERVICE), countdown maintenance reminder time; When the maintenance time is coming, the service warning icon will flash to remind. SPEEDOMETER：Accurately records your RPM when engine is running, helps to adjust engine idle speed ; can be programmed for different engine firing modes. REPLACEABLE BATTERY：Internal replaceable CR2450 battery, data retained after battery replacement; When the engine is stopped, the player will automatically turn off after 2 minutes; press the button to read the screen, data retained after shutdown.