Dunlop cricket tennis balls country of origin Philippines improved durability & performance exclusive dura- weave felt mejore durabilidad y rendimiento gracias al filtro dura-weave extra duty extra durabilidad idea for longer play on all court surfaces. idea para jugar durante más tiempo en todas las superficies. exclusive felt from tex tech industries. modern tennis balls must conform to certain criteria for size, weight, deformation, and bounce criteria to be approved for regulation play the itf's play and stay campaign aims to increase tennis participation worldwide, by improving the way starter players are introduced to the game. the itf recommends a progression that focuses on a range of slower balls and smaller court sizes to introduce the game effectively to both adults and children. the slowest balls, marked with red, or using half red felt, are oversized and unpressurized, or made from foam rubber. the next, in orange, are unpressurized normal sized balls. the last, with green, are half pressured normal sized.