Features: This product is a multifunctional speed measuring/counting table with speed measuring function, counting function and upper limit alarm output function. It is generally applicable to all kinds of mechanical equipment such as harvesters, fan, etc, where the speed of devices needs-to be measured. This product is compatible-for Hall switch, metal proximity switch, infrared-proximity switch and other detection switch signals. This product can output an NPN-alarm signal, and the user can connect an indicator lamp-and a sound-generator for warning. Users can customize the alarm field-value. The sensor of this product is a three-wire sensor, which adopts electronic technology, so that the sensor has high sensitivity, strong reliability, good anti-interference performance, stable operation in the growth period, and can be used for speed measurement and counting. This product adopts hall sensor for speed measurement, and through the internal function of the program, one probe-can be used to detect multiple-points, thus improving-the detection accuracy. Multi-period average velocimetry is used for speed measurement, which has a wide low-speed and high-speed measurement range-and excellent measurement accuracy. The counting function is realized by the external counting function of the-timer of the single chip microcomputer, and the counting is stable and reliable. Specifications: Material:ABS Working-voltage DC9-24V The speed-range of single detection point in basic-range is 30-80000rpm. Display 4-digit 0.56 inch red-digital tube Overall-dimensions 78x42x24mm Opening size is-76.5 x 39.5mm. Installation mode-embedded installation Working temperature is 0 to 60 Note: .Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. .Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1x Tachometer