The Small Color Size Cylinder Blocks (A021-3) extend cylinder work by introducing both color and graduated size as simultaneous variables, offering a richer sensorial challenge than the standard Cylinder Blocks for children ready to move beyond single-attribute discrimination. This material is well-suited for the 3.5–5 age range as a follow-up exercise once children have mastered the knobbed cylinders and are building more refined visual discrimination. It adds useful complexity to your sensorial sequence without duplicating materials already in your environment.