Pound the colorful balls with hammer and watch it rolling down to bottom. Placing it back on it's same place matching with exact ball colors. A good hand-eye coordination helps toddlers to learn the color difference. A natural wooden has been used and vegetable dye colors are used. Please note: Do not leave your children alone while playing. Toddlers have a habit of keeping anything in mouth and these balls are very small to swallow or get choked in throat. Happy playing.