The nozzle pad is an essential component of the cleaning mechanism in the BallStar system. It is responsible for applying the liquid cleaner onto the balls during the cleaning process. It's important to note that there are two different varieties of nozzle pads available: one for the Old style machine and another for the New model. While they may appear similar, it's crucial to use the correct nozzle pad for your specific machine as they are not interchangeable. Differentiating between the two is relatively simple. The Old model nozzle pad features a hole at the back for injecting the liquid cleaner, whereas the New model does not have this hole. By identifying the appropriate nozzle pad for your machine, you can ensure optimal performance and effective cleaning. Trust your observation skills, and you'll easily determine the right nozzle pad for your BallStar system.