These balls are the same size as M-class balls, used in batting cages, etc. There are no cracks in the balls. They can be widely used for team practice and individual practice, such as in youth baseball and recreational baseball. *Regarding the quantity, we can accommodate requests from 20 balls, so please comment. *We have a large stock. When shipping, we will wipe each ball individually, pack them in bags, and ship them in a cardboard box. *If you buy them now, we'll give you 5 extra balls! *We may have flash sales, so please like and purchase. Instant purchase is OK ⭕️ #baseball #baseballgear #battingcage #softball #softballball #bat #youthbaseball