No Battery Required-connects to spark plug wire. Works on any gasoline engine. Indicates operation in RPMs and hours. Tach Hour Meter Digital Gauge Motorcycle ATV Tachometer Engine DESCRIPTION : 1  No Battery Required-connects to spark plug wire.2  Works on any gasoline engine.3  Indicates operation in RPMs and hours.4  Easy Installation no power or ground required.5  Maximum RPMs 99999, Maximum Hours:999996  Easy to set 1, 2, 4, cycle engine for manual7  MAX RPM can be showed, MAX RPM can be reset8  Waterproof 

Tach Hour Meter Digital Gauge Motorcycle ATV Tachometer Engine