Learning That"s Right on Track * Young thinkers can build unbelievable ball track structures with this simple stacking plank system * Create ramps, funnels, chutes and crazy contraptions like the "Black Hole" and "Bounce Plate" * No glue, no connectors-just loads of constructive fun! Includes 400 identical wooden planks, 2 specially designed lightweight balls for maximum action and an 18-page idea book with project photos and quick-start instructions * Contraptions planks are made from pine