Through fine grinding and polishing process the block edges are round and smooth without any burrs which does not hurt children's hands. It includes 17 instruction cards of different difficulty to help children to finish. These cards in bright color are cute and attractive perfectly appealing to children. Manufacturered by N-R. They can build various patterns with the building blocks which greatly cultivate their patience concentration thinking imagination and hand-eye coordination. Give them this toy that will keep them happy and entertained for hours while you have hours of peace and quiet to do whatever you need to do. Made from high quality natural wood material with eco-friendly water paint these blocks are wear-resistant and scratch-resistant to play with.