The cuisenair learning rods include 222 unit rods in 10 sizes. The smallest one is 1 cm & the tallest one is 10 cm tall. This is a great set for kinder and preschoolers to learn mathematics, counting, fraction and develop motor skills, logical thinking. The set comes with 6 guide boards ranging from easy to difficult. (designs may vary) Made out of plantation timber using non-toxic materials. 3+