This eco-friendly puzzle is a top choice, having won the Dr. Toy 100 Best Products and the Parents' Choice Approved Award. This environmental friendly Geometric Stacking Puzzle is made of wood from FSC-monitored sources, painted with water-based paints, packaged in a box made of recycled materials, and printed with soybean ink. Each of the four puzzle pieces contains one, two, three, or four posts for children to stack a circle, rectangle, square, or triangle on. Each shape is made with a different number of holes so it can only be put on the correct puzzle piece. It’s just the right size for little hands and the characters are captivating, too. Tested to meet European and U.S. safety standards.