Butterfly 3-Star Tennis Ball (Pack of 3), White, 40 mm Conveniently sold in a 12-pack, the 3 Star 40+ Plastic Ball is the official ball of the 2015 World Championships &, The new ITTF approved plastic ball is required for use in all ITTF sanctioned events and will be used at select events in North America Regulation 40mm ITTF Approved