SENDEC HOUR/TACH MAINTENANCE METER (4188)For 1 or 2 cylinder gasoline engines. Use to allow regular preventive maintenance. Benefit with increased fuel economy, less downtime, and longer engine life. 3 Functions: Hour Meter: records actual running time of engine (non erasable) Service Alert: warns when lube & oil change is needed in 25 hour intervals Tachometer: displays RPM up to 9,000 RPM Easy installation. No wire stripping or soldering required. All you need is a 1 8 drill bit and a