From the Gears toy description:
Build 6 working models including a gearbox, a hand drill, an egg beater, a helecopter, a rotating sign, and a high speed fan. A 40 page activity book is uncluded with innovative experiments and detailed explanations of various technical and scientific principles and how they are applied. The Engino Toy System is perhaps the most advanced and versatile three dimensional construction toy in the market today. It offers both children and adults unique opportunities for design and creation.
Here's where you can get Engino Mechanical Science: Gears.