Physical Install :

Install the encoder flywheel onto the main shaft of the DC motor, and allow the flywheel to fit into the gap of the Speed sensor, as shown in the picture below:


Pin Connection:

Speed Sensor Arduino
Output Pin(data pin) D2
VCC 5V
GND GND

Software Download Link:
1)Download Timer library from following link:
https://osoyoo.com/driver/v2.1car/Timer.zip

After you get the file in your download folder, do Not unzip it. Instead, directly import the whole zip file   to Arduino IDE :
Open Arduino IDE ->Sketch ->Include Library ->Add .Zip Library

2)Software Test:
https://osoyoo.com/driver/v2.1car/lm393test.zip
After upload the lm393test.ino file to Arduino, Open Serial Monitor

Rotate the wheel which connected to Speed sensor, the serial monitor will show the rotation speed.