●【Application】:Working voltage range: AC/DC 5V to 277V, suitable for most small gasoline engine. ●【Hours Meter】 : Keep track of total usage time up to 99999H.The maintenance time is defaulted at 50 H,ability to reset the maintenance interval. ●【Signal Detect】:2 Kinds of method to connect the signal(connect pins/connect spark plug wire),positive and negative poles are non distinctive. ●【Water &Shock Resistance】: Display with PC transparent board and 100% epoxy resin sealing craft can keep it away from the damp or moist, which also prevent the strong shock between transport or cleaning. ●【Others】:Snap-in design for standard panel cut-out size: Approx.0.123x0.08 feet(37.5x24.5mm);Built-in CR2050 battery for date retained when power-off; 2-years service and support for after-sales and technical group.