Product Name: Digital Tachometer Features: Instrument with a large LCD display. Waterproof and easy to install. Measures rotational speed inductively by bringing the ignition cable near the engine. Measurement methods include holding the meter 3-5 cm from the spark plug cable or using a metal clip to attach the sensor to the cable. Suitable for engines with speeds up to 25,000 rpm or more. Compatible with 2-stroke and 4-stroke gasoline engines. Widely used in dirt bikes, go-karts, ATVs, two-stroke chainsaws, and lawn mower engines. Auto zero hour reset function with hour meter tracking up to 10,000 hours. Speedometer can display speeds up to 99,999 rpm. Displays current speed when the engine is on and total operating hours when off. Programmable maintenance reminders for oil changes and other services.