Iztor Water Proof Hour Meter/Service Gauge for motorcycle Dirtbikes Go-karts, Boats, ATV Jetskis black Works on Any Gasoline Engine. Track the Service Life of Your engine - oil changes, valve, adjustments, spark plugs, etc.. No Battery Required - connects to spark plug wire. Easy Installation-peel&stick,no wiring necessary,or attach with enclosed hardware. No Battery Required-connecys to spark plug wire. Works on Any Gas Engine. Records and Displays to 9,999.9 Hours.Stand-by Time up to over 20,000 hours. Hour Glass Symbol Appears and Flashes on/off to Indicate Counting Time