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 6.4cm/2.52inch, making them resistant to hard hits and able to maintain their shape even after repeated use Resilience Effect: It features a resilience function, adding an extra challenge to your training sessions and improving your reaction speed. The tennis ball ensures long term use even with frequent training sessions Wide Application: These Training Balls are nice for various scenarios such as tennis sports, outdoor training exercises, tennis games, competitions, etc. 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 your family members or friends who love playing tennis, these tennis balls will enhance your skills and add fun to the game Specification: Material: Rubber, Tennis Felt Size Chart: Diameter: 6.4cm/2.52inch Package Includes: 6 Tennis Balls Note: Please allow slightly errors 1-2cm differences due to manual measurement.