Set of 4 knobbed cylinder blocks kids childrens educational toys Good for developing children visual discrimination of size volume thickness and height improving eye and hand coordination and enhancing fine motor skill. The Knobbed Cylinder Blocks can help your child develop even more his visual sense as he recognizes different sizes. The toy allows for many uses as it can be played with one, two, three blocks or all together at the same time, making it more challenging as the cylinders get mixed. The child has fun searching for the right hole that fits the cylinders and discovers the progression that each block unfolds. Contents : Set of 4 knobbed cylinder blocks.