Happy Puzzle Company The Amazing Clock Kit - Construct your own colorful real working clock. Educational toy that teaches how clocks work, and doubles as an actual wind-up clock. LEARN BY BUILDING: Let your child learn how clocks really work by building one themselves. Learn how gears work, what the pendulum does, why the arms move, and how the bell works. STEM FUN: Your child will feel like a little engineer after building their own little clock. Wind it up for up to 6 hours at a time. COMPLETELY TRANSPARENT - This clock is completely see through, so children can keep learning once they've built it. They'll see the parts all working together to keep time. 31 PIECE KIT! This kit includes everything you need to build a clock from start to finish, no tools or batteries needed! Spin the cogs, check out the springs, watch the arms & bell. EDUCATIONAL - by building this clock, your child will learn about cause & effect, transfer of energy, engineering, keeping & telling time.