Rainbow Stacking Rings by PlanToysRainbow stacking rings by PlanToys. Helps teach children about size and colours, with a foldable central rod for safe play. Perfect for fine motor, coordination, mathematical, creative and communication skills. 15. 5cm Tall 8cm Diameter. Made from natural rubber wood trees that no longer produce latex. To keep the wood pure, no fertilizer is added to the soil three years prior to cut the trees down. To strengthen the wood, PlanToys uses a chemical