Engino Discovering STEM Mechanics Gears & Worm Drives | 12 Working Models | Illustrated Instruction Manual | Theory & Facts | Experimental Activities | STEM Construction Kit Engino brings complex concepts into clear focus for budding engineers and Scientists with award winning components and step by step illustrated assembly instructions Discover how gears can reduce or increase speed and learn how Worm drives are used to change rotational speed Build 12 working models such as a helicopter, vise, hand drill, scissor lift, and more Includes 16 pages of theory and facts, a 3 page quiz, 6 pages of experimental activities illustrating uses of gears and Worm drives, 17 pages of step by step, 3D rendered illustrations Builds illustrated online at Engino website or using the Engino 3D app downloadable free for Android or Apple iOS. Made in CYPRUS Designed and made in CYPRUS - no batteries required