Professional: This tennis balls with drawstring bag are suitable for both adults and children for training purposes.Material: Made from rubber and tennis ball felt, these tennis balls are designed to be premium and withstand heavy use.Size: Each tennis ball has an approximate diameter of 6.4cm/2.52inch, making it the great size for standard tennis training.Performance: With an elasticity range of 1.1m to 1.15m, these tennis balls provide great for effective practice sessions.Packaging & Storage: The set includes 12 tennis balls packed in a drawstring bag for easy storage and transportation. Specification: Material: Rubber, Tennis Felt Size Chart: Diameter: 6.4cm/2.52inch Package Includes: 12 Tennis Balls Note: Please allow slightly errors 1-2cm differences due to manual measurement.