Haba Kullerbu Traffic Jam Ball Track SetThe balls are racing down the momentum track when what's this? They're stuck in the ball collector! When they back up, the "stop and go" lever's released and they can race together again toward the funnel. Then it's back onto the track and heading for the dominoes! Balls measure 2" in diameter. Made of beech wood and ABS plastic. Can be combined with other Kullerbu ball track sets and accessories to create bigger and better layouts. Measures 18. 5" x