Features 1、0‑30000RPM MEASUREMENT RANGE: This digital chainsaw tachometer can measure speed up to 30000RPM, suitable for two stroke single cylinder engines, four stroke two cylinder engines, and gasoline engines that ignite once a week 2、SIMPLE ROTATION MODE SETTING: Press and hold the MODE button of tachometer, and the screen will display 01RPM, 02RPM, and 03RPM in sequence(corresponding to the number of revolutions of various engine strokes). The factory default setting is 02RPM speed mode. Release the button with your finger to flash the data display for 3‑5s. After stopping, confirm that the rotation mode turn on and you can measure 3、RESET FUNCTION AND BATTERY REPLACEABLE: Hold down the Reset button of tachometer, then the data will return zero. Simply open the battery box to replace the battery when run out. Required battery model is CR2450(not include) 4、EASY TO USE: Due to the inductive design, the tachometer work and start to test once placed near the spark plug cable of the engine. Just keep the meter between the spark plugs 1.2‑2in and then test; insert the pick up wire into the hole of the meter and clamp the metal clip on the spark plug cable 5、WIDE APPLICATION: Pulse engine tachometer is widely use to test the engine speed of gasoline chainsaws, gasoline grass cutters, riding lawnmowers, gasoline motorcycles, ATVs, off road vehicles, portable generators, and more Specification Item Type: Speedometer Material: ABS and PCB Speed Range: 100RPM-30000RPM Battery: 1 x CR2450(not included) Package List 1 x Tachometer 1 x Spark Plug Wire 1 x User Manual