50 wooden blocks in plain wood, primary and secondary colours fit neatly into a wooden trailer on wheels that could be used as a pull along toy to begin with. The blocks are related in size so they are easy to use, and offer a wide range of construction possibilities. From the instructions on the packing children will identify the mystery of secondary colour creation. It is also used for development of coordination and colour recognition and problem solving skills. Made of cultivated and non-toxic coated wood.