KENKO SOFTBALL Kenko Softball 6 balls, half a dozen Size 3, cork core (Certified by) Japan Softball Association Certified ball, size 3, set of 6 NEW TYPE ※ As shown in photos 3 and 4, there are 5 certified balls and 1 rotating ball, for a total of 6 balls. How about these for winter training or the transition period to actual games in early spring!? Thank you.