Features: This product is a multi-function speed measuring/counting meter with speed measuring function, counting function and upper limit alarm output function. With reliable performances, simple installation and wide application range, it is generally applicable to all kinds of mechanical equipment, such as harvesters, machine tools, motors, fans, etc., where rotational speed measurement is required for devices, as well as production counting and other occasions. This product is compatible with Hall switch, metal proximity switch, infrared proximity switch and other detection switch signals. This product can output a channel of NPN alarm signal, and the user can connect the indicator light and sounder for warning. The user can customize the alarm field values. The supporting sensor of this product is a three-wire sensor, which uses electronic technology to make the sensor have high sensitivity, strong reliability, fine AntiInterference performance, stable operation in the long term, and can be used for speed measurement and counting functions. This product adopts Hall sensor for speed measurement. Through the internal function of the program, one probe can be set for multiple detection points, thus improving the detection accuracy. The speed measurement adopts the multi-period average speed measurement method, which has a wide range of low speed, high speed measurement and high measurement accuracy. The counting function is realized by the external counting function of the single-chip timer, which is stable and reliable. Material:ABS colour: Blue Package Contents: 1 x Motor speed detector Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.