Features: A game of chain reactions: The magic of connected movements: slow at first, then acceleration until the circuit concludes elegantly, and sometimes musically. Game of understanding: Understand the ingenuity of a chain reaction, learn how speeds vary depending on the weight of an accessory, and evaluate distances between accessories. Game of construction: Summon up all your skill and dexterity to position the accessories and create a circuit. 25 piece construction set Compatible with the other kits All Djeco products are made from the highest quality materials, all are completely non-toxic and meet and exceed all US and European testing standards A perfect STEM Activity for ages 7-99. Beginning in France in 1954, DJECO creates award winning, timeless children’s products dedicated to quality, value and child development.