Features 1、0.56inch 4‑digit LED screen clearly display RPM readings in green. 2、Come with 3 wire NPN Hall Proximity Switch Sensor. 3、Revolution speed measurement up to 9999rpm. 4、High precision, quick response, stable and reliable. 5、8‑24V wide supply voltage, suitable for various applications of RPM speed measurement. Specification Item Type: Tachometer Display: 0.56inch green LED, 4 digit reading Measuring Range: 10-9999rpm Measuring Accuracy: ±0.1%, reading±1digit Display Refresh Rate: >3 times/sec Overrange Display: Display "1" or "-1" in the first digit position, none in the last three digit positions Hall Proximity Switch Type: NPN NO Tachometer Size: 79x26x43mm / 3.11x1.02x1.69in Package List 1 x LED Tachometer 1 x Hall Proximity Switch 1 x Round Magnet 1 x Cable