3021 Odyssey II Tachometer - Resolution 100 RPM - 3.375"High quality digital instruments that offer stable, accurate and easy to view readings. Teal display offers high contrast visibility, even in sunlight. All gauges have machined aluminum housings, chrome front bezels and non glare, scratch resistant lenses. Have 0 18,000 rpm range and easily adjust for combinations of one to fifteen cylinders without using coils; push button calibration. Work with single or dual fire ignitions. Display rpm and high rpm