The 8-blade replacement impeller for the BallStar system is specifically designed to clean 8 standard billiard balls per cycle. It is available for both the Old and New models of the BallStar system. While the exact technical difference between an "impeller" and a "propeller" may vary, in this context, the impeller refers to the rotating mechanism responsible for cleaning the balls inside the BallStar unit. With this replacement impeller, you can ensure that your BallStar system continues to effectively clean and maintain your billiard balls, providing you with a convenient and efficient solution for ball cleaning.