Wooden City wooden 3D puzzle open clock The open clock is not just a 3D puzzle, it really works! Once you have put it together, you can see the whole mechanism and let yourself be fascinated by the turning of the hands of the clock. To make the pendulum move you put a coin or in it in the secret compartment of the weights. Depending on the weight of the coin in the pendulum, the clock will run faster or slower. The clock is ticking for about two hours. Specifications: Gender: unisex Material: wood Colour: brown Clock dimensions: 32 x 52 x 6.4 cm Package size: 35.5 x 24 x 4 cm Age: from 12 years old