Mizuno Red Mark - 40 tennis sponge balls These will be shipped in a recycled cardboard box! Since Mizuno currently sells these for 1,100 yen for 2 balls, 40 balls would be equivalent to 22,000 yen. They are popular, so they sell out quickly. We recommend purchasing soon after liking the item! Because they are sponges, they are light and easy to handle, so they can be used for baseball toss batting practice, toss tennis with children, and throwing practice! Some facilities also use them for grip strength training. They were used for tennis in a gymnasium for about 4 hours, so there may be some wear and tear from the strings, and the degree of deterioration varies depending on the ball, so there may be differences in the strength of the rebound. Please understand that these are used items and there will be differences from new ones before purchasing.