Build your very own Calico Cat with the smallest building blocks in the world! A great gift for cat lovers! The finished nanoblock Calico fits perfectly in the palm of your hand. A moderately challenging building set for beginner building block fans, the nanoblock Calico building set features 140 micro building blocks allowing you to build in greater detail. Includes detailed color instructions. Definitely not designed for children under the age of 8 years since the pieces are very tiny. Level of difficulty on this one is a 2 - with "5" being most difficult.