Crystal Polydron Basic Set

The same 164-piece starter set, but with clear pieces mixed in among the red, yellow, blue and green — and that changes what it's for.

Put it on a light table or against a window and your child can see inside the shape they've built. The solid walls stay solid; the clear ones open the whole thing up. Understanding the space inside a cube is much easier when you can look into it.

Squares measure 7.5cm. Exploring booklet included.