Iztor Waterproof Hour meter Tachometer 2 & 4 Stroke Small Engine Spark For Boat Outboard Mercury Applications for all 2-Stroke or 4-Stroke gas powered engines,Water resistant, It will show both engine RPM and hours of operation,Read up to 99,999 RPM Waterproof Ip65easy to install, instructions & user manual included,Programmable maintenance interval setting Can reset total hours and maintenance time,Wrap first wire around your spark plug cable, connect second wire anywhere on the engine or frame Great for Cart Engines operating in the 25,000 + RPM range. Battery life: 3 years or more