☆ Mizuno Black Mark (Selected Balls) Sponge Tennis Balls, 12 balls. ☆ Product number: 60H-803. Size: Diameter 7cm, Weight: 15g. ☆ Used for about 1 hour indoors in a sponge tennis circle. ☆ I have selected balls that I think are in good condition. ☆ I think they are good for children's tennis practice and for toss batting in baseball. ☆ Simple cleaning has been done. ☆ This is an item from a club, so I cannot offer a discount. ☆ Shipping will be by regular mail. ☆ There are no smokers or pets.