Premium Range – Four wooden boxes with red, blue, yellow and green lids. Each box contains 10 cylinders of the same colour. The cylinders in each box vary in height and/or diameter. Yellow set: height and diameter of the cylinders decreases. Green set: diameter decreases as the height increases. Red set: diameter decreases as the height remains constant. Blue set: height decreases as the diameter remains constant. The child first works with one set of cylinders ordering or stacking them and can then work with the sets combined. This activity gives the child a clearer understanding of the different dimensions and their interplay. The Premium Range knobless cylinders are coated with chip free paint and are ideal for frequent use.