The Yamaha ENG-METER-4C-01 Deluxe Engine Meter (Hour/Tach) helps you keep track of your engine's operating hours. The Deluxe Engine Meter includes pre-programmed service intervals at 10 hours (initial) and every 50 hours thereafter. A flash alert displays for a 2-hour period upon reaching the specified interval. It includes hour meter and tachometer functions. The operating temperature is -40-degrees Fahrenheit to 160-degrees Fahrenheit. The -40-degree Celsius battery life is 7-10 years (non-serviceable). It works with all Yamaha gasoline generators and pumps.