Tach Hour meter Motorcycle Meter Digital Tachometer Engine Resettable Maintenace Alert RPM Counter For Chainsaws Boats ATV    1.【No external power required】- Timed by sensing the vibration intensity and amplitude of the machine; The hour meter contains a battery inside. 2.【Accumulates Total Running Hours)】- When equipment vibrates, the display shows the total run time of the machine and remains visible. Help you track how many hours you put on your machine. 0.1-hour accuracy. 3.【VIBRATION SENSITIVITY】- Programmable vibration sensitivity. Used to accurately sense the vibration frequency of different machines during operation. Hour meter contains lock function to prevent time usage during transport. Power saving mode to conserve battery life with auto sleep time. 4.【1.Easy To Install】-Along with two side holes for fastening,no wiring necessary,or attach with enclosed hardware.