STEM Circuits XL Chain Reaction Kit Construction set to build your own chain reaction model, in which one reaction triggers another reaction, with interesting surprise effects. Give the starting signal and discover the function of the pulley, lever and gearbox in play. Isn't that enough? Chain reactions can be expanded with everyday objects and encourage creative construction. With the help of the instructions, three unique chain reaction models can be built, each more spectacular than the other. There are no limits to creativity. Young inventors can create their own routes and can also integrate non-Fischertechnik pieces, such as dominoes and the like. Can be combined with the 551588 Chain Reactions and 569018 Crazy Chain Reactions building sets Nominated for the "German Toy Award 2021" Nominated for the TOP 10 Toys 2021 "spiel gut" award Assembly instructions to build 3 complex and original domino circuit models. Contains 682 pieces. Recommended age: +8 years. Made of plastic. According to EN71&ASTM regulations. WARNING: Not suitable for children under 3 years, contains small parts. Adult supervision is recommended during play. Read the instructions before use, follow them and keep them for reference. Made in Germany by Fischertechnik.