Basic sequence of sorting. Set comprises of five colorful tubes. Children are able to learn about size, color and scale. Under the Green Concept Design PlanToys selects only eco-friendly materials and manufacturers utilizing a minimal waste concept. PlanToys long-term commitment to social programs promotes healthy child development and environmental protection. All PlanToys are made using chemical free, kiln-dried recycled rubberwood and designed with water based non-toxic colors as accent. A small wooden playthings can produce big change. Through innovation and commitment to design excellence, PlanToys team of child development experts play a critical role in developing their selection of diverse wooden toys.