Hour Meter Hour meter keeps track of important maintenance times for oil changes, valve adjustments, spark plugs and more, Usable with any gas engine, Records and displays up to 9,999.9 hours; hours automatically roll over, Includes log book to note oil changes, service intervals, etc., Peel and stick or attach with supplied hardware, Connects to spark plug wire, so no batteries are needed, Safely and completely encased in epoxy, Made in the U.S.A.