Works on all gas engines (including newer fuel injected four cycle engines) Tracks total hours on motor, non-resettable Measures tach up to 20,000 RPM in real time Measure and records max RPM, resettable Spinning-arrow activity icon Adjustable settings for Fast/Slow updates, Hi/low spark sensitivity (for electrical noise suppression) 99,999 Hour Digital Display Spinning-arrow activity icon Peel-n-Stick or Bolt-on