GuangYa SH78 SERIES digital hour meter DC/AC Powered Hour Meter/Service Meter SH78-1Digital Hour Meter/Service Meter Technical DataCapacity:19999.59 Run-time,Total-time and three Service-timers.Control Buttons: 2 Simple control push buttons.One Run Timer: Counts up and is Resetable.One Total Timer:Counts up & Resetable by dealer ONLYThree Service Timers:Resetable timers that counts backwards to 0 and then activates SOS1,2,3 alarms.Alarm can be canceled and the settings can be reset or changed at any time to a new setting.Automatic continuous SOS 1,2,3 reminder until that timer or timers are reset or new times are set.Timers: Activated by leas wires of 6-40 volts input DC/AC or alternator power.Display Height: 6mm Five digit plus Two 4.00 Total of 7 digits.19999.59 hours.Auto ON and auto OFF: Can automatically switch between the internal replaceable battery and the external power source to view the LCD display.Operating Currents:6 to 40 volts AC/DC alternator or AC/DC energy produced by external battery or magneto engine kill wire.Optional Replaceable DC 3 voltCR2032 battery for non-external onput viewing when engine is not operating.Operating Temperature:-32+185Vibration resistance:Withstands 10 to 75HZ at 1-8gAccuracy:Better than +/-0.01Humidity:100Water proof:Totally submergible for watercraft applications.Protected from:Alternator load dump.Inductive switching and reverse polarty.Memory:CMOS EEPROM Non-volatile memory has retention in excess of 10 years without power.Case Style: Standard replacement Panel Mount with 2 mounting holes.Meter comes with a plastic snap-on retaining clip for quick mounting.