The Yamaha Digital Tachometer is a very welcome addition to any helm. See RPM, oil pressure and engine coolant temperature. 2 Stroke engines will display oil level. Also see engine trim, total hours, trip hours, and water detection. Battery voltage, and periodic maintenance intervals as well. Also, if your outboard is equipped with VTS – Variable Trolling Speed you can use this tachometer to adjust your trolling RPM is 50 RPM increments.