Roll, CLUNK, discover!. Meanwhile, fine motor skills are bolstered and an understanding of size and color is fortified - Plus, the balls all have built-in rattles for an extra twist of sensory fun! The gradually widening track propels the balls forward fast until suddenly they drop, perfectly, gracefully into their matching colored slots.Includes sorter and 4 balls. RollAgain Sorter Learning Toy For ages 12 months and up.