This is a genuine KitchenAid replacement stand mixer Hall Effect Sensor, this sensor is commonly referred to as the “ribbon wire” and runs from the speed control board to the motor. This sensor will fit all 5 Quart and 6 Quart Professional Stand Mixers made by KitchenAid.
If the speed on your KitchenAid stand mixer runs erratically this sensor may need to be replaced. The most common sign of a sensor failure is if your mixer increases its speed to full and then shuts down on its own.