<ul><li>Wide range of scales</li><li>Multiple signal sources</li><li>Rugged, Reliable construction</li><li>7 character LCD display</li><li>0-999999.9 Hours</li></ul> Chesapeake White SS 4" Tachometer with Hourmeter - 6,000 RPM (Gas - Inboard) 4" - Hole size: 3.375" (85mm) Electronic tachometers work by counting pulses generated by the ingition system, alternator, tach signal generator or magnetic pickup sender. The tach is hooked up to +12VDC, Ground and one of hte signal sources listed above. By selecting the right tach and setting the switch on the back to the correct postion you let the tachometer know how many pulses are sent per each engine revolution. Benefits: Wide range of scales Multiple signal sources Rugged, Reliable construction 7 character LCD display 0-999999.9 Hours Updates in .1 increments

1 - Faria Chesapeake White SS 4" Tachometer w/Hourmeter - 6,000 RPM (Gas - Inboard)