1. LCD display, low voltage design, built-in battery (CR2450) power supply, inductive design, safe and reliable. 2. Multiple measurement methods: After connecting one end of the electronic wire to the tachometer, use a metal clip to attach it to the spark plug wire sheath for inductive measurement; wrap the electronic wire around the spark plug wire sheath several times to sense and measure; or hold the tachometer 3 cm to 5 cm near the spark plug wire sheath for measurement. 3. (1) Timing range: 1 minute to 99999 minutes (MIN). (2) Speed mode setting: Press and hold the SET button; the screen will cycle through 01, 02, 03, 04. The default factory setting is 02, which corresponds to common engine stroke configurations. Release the button when the desired mode is displayed; the value will flash for 3 to 5 seconds before confirmation. (3) Shutdown and reset: Hold the SET button until the display reaches 04 and flashes for 3 to 5 seconds. Then press and hold both MODE and SET buttons simultaneously until the screen clears, resetting stored operating time and speed data. (4) Press and hold the MODE button to view historical maximum speed data. (5) Suitable for various equipment: gasoline engines, chainsaws, lawn mowers, motorcycles, automobiles, karts, engineering vehicles, snowmobiles, ATVs, motor boats, grinders, generators, vibration machines, and other mechanical devices. Type: Digital Tachometer Measuring Range: 10020000 RPM Measurement Accuracy: 1% Resolution: 1 RPM Power Supply: Button battery Color: As shown in picture Material: Plastic Package Contents: 1 x Tachometer Note: Light reflection may affect display visibility.