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 or individual practice in youth baseball, recreational baseball, etc. *Regarding the number of balls, 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 it now, we'll give you 5 extra balls! Instant purchase available ⭕️ #baseball #baseballgear #battingcage #softball #softball #bat #youthbaseball