Kid Advance Montessori Knobless Cylinders

4 sets of 10 cylinders varying in height and/or diameter in each set. Each set is in a separate wood box with the lid painted the same color as the cylinders: red, green, yellow, and blue.
Develop a child's visual perception of dimension. It also provides experiences in comparison, grading, and seriation - indirect preparation for mathematics.
Dimensions of each wooden box: 6.5 x 4.5 x 2.75 Inches.
Recommended ages: 4 years and up.