Ideal for nursery kindergarten and younger children XL Polydron is four times the size of Giant Polydron and they fit together perfectly. This starter set is ideal for smaller groups of children looking to build a smaller tower with squares and triangles.This 12 piece set contains 4 Squares with 16 holes 4 Squares with 4 Holes and 4 Triangles and a guide. Sides of squares measure 40.5cm. Age 2+.