Used tennis balls, used outdoors for practice. Mostly Saint James, plus Head Pro, Dunlop, Yonex, Penn, etc., for a total of 100 balls. The condition (air pressure, dirt, wear and tear) varies. These were used by my family, so I don't know much about them professionally ^^; I'm not sure how well they'll perform for their original purpose, but would they be suitable for those who need a lot of balls, such as for children's serving practice, ball machine practice, or baseball batting practice? Please understand that these are USED items before purchasing. Thank you very much ( ⁎ᵕᴗᵕ⁎ )