Sensory Tumbling Balls by PlanToysSensory tumbling balls by PlanToys. Set of three different sensory balls for touch, sound, and sight. 6cm x 6cm x 5. 5cm. 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 free kiln drying process. All PlanToys are made using certified E Zero formaldehyde free glue in place of traditional