Based on a retro-style mechanical timepiece, this 3-D puzzle features a precise pendulum mechanism that will challenge your analytical skills and fulfill your fulfillment is also doubled. After fully wound up, it can keep working for 3~4 hours maximum, prolonging the building fun as much as you want.

a gravity-swing pendulum with precise anchor escapement

appealing outlook of mechanical engineering

double fun of model building & brain teasing

perfect gift for mechanical lovers or family & friends