What kind of effect does air volume control screw have?

For example, suction and release can be made very smooth indeed.
You can change the air flow rate using the airflow adjustment screw according to the object’s weight and size.
When you are handling a very light and very small object, completely loosen the screw to smoothly release the object. When you handle a heavy object, tighten the screw to increase the suction force of the air pit.