Get rolling with an endlessly reconfigurable wooden chain-reaction builder designed to spark hands-on STEM play. This set contains 178 precision-cut pine planks plus dowels, reaction balls, a bell, string, a bowling pin, a toy car and a 16-page idea book with photo projects and quick-start instructions—everything kids need to design ramps, tunnels and clever trigger mechanisms that set off satisfying reactions like ringing a bell or toppling a pin. Stacking and balancing the solid planks teaches proportion, balance and basic physics while encouraging creativity, problem-solving and cooperative play at home or in the classroom. Ages 7+.