100% safe food grade chain: Baby chewing chain is made of real silicone, BPA/PVC free, phthalate free and lead free. Soft and easy to bend. Durable silicon material: High-quality sensory necklace is made of silicone material, which is nontoxic, neutral in flavor and resistant to high temperature up to -40 ~ 230 degrees. It is convenient and durable to chew. Reduce the baby's fear of tooth growth: Children's chewing chain provides safe chewing tools for children with toothache, autism, SPD and other special bed pillows. It helps to keep teeth growing healthily, while reducing stress and increasing concentration. Portable adjustable rope: Collar with sensory teeth that can carry free rope. Children can wear whatever they want. They are not worried about losing it. It can also develop the baby's grasping ability