Quality Material: These tennis balls are made of rubber and tennis felt, featuring a soft inner core and comfortable grip. They offer great elasticity and durability, allowing for long-term repeated use. Features: These training tennis balls have a diameter of approximately 6.4 cm, making them resistant to hard hits and able to maintain their shape even after repeated use. Resilience Effect: They feature high resilience, adding an extra challenge to your training sessions and improving your reaction speed. The tennis balls ensure long-term use even with frequent training. Wide Application: These training balls are suitable for various scenarios such as tennis sports, outdoor training exercises, tennis games, and competitions. They can also be used as interactive toy balls for playing with dogs. Great Gift: This set of tennis ball toys makes a great gift for family members or friends who love playing tennis. These tennis balls will enhance skills and add fun to the game. Specification: Material: Rubber, Tennis Felt Size Chart: Diameter: 6.4 cm Package Includes: 6 Tennis Balls Note: Please allow slight differences of 1–2 cm due to manual measurement.