Used tennis balls 42 DUNLOP HD balls. Used for 8 weeks, 2 hours twice a week on an omni court. The felt is not very worn and there is no noticeable loss of air, so the feel when hitting is very good. They can still be used for ball feeding, serving, etc. They are also fine for stroke rallies and can be used for games. Please purchase only if you understand that these are used balls.