If your home or bar pool table has an automatic cue ball return with weighted mechanisms, you should have a special replacement cue ball on hand so play is never interrupted. These high quality Weighted Cue Balls have a slightly heavier weight than standard balls, to allow the weight-sensitive mechanism to separate the cue ball from the rest.. After a scratch, the cue ball is separated from the number balls and returned it to the end of the table. For use with select Valley-Dynamo tables.