Expert developed; Parent preferred. Activated by child's bite! Filled with sanitized drinking water. cooling comfort. Gentle massage. Multi-texture for relief. Our goal, always, is to make the best possible products for you and your baby. To do this, we work in consultation with Dr. T. Berry Brazelton, Dr. Edward Tronick, and their staff of specialists at the Child Development Unit, Children's Hospital, Boston. We also listen to the members of our own worldwide Parents Council, who are real parents, just like you. Massaging action & cool comfort - ideal for gum relief. Teething babies who haven't cut their first teeth yet love to chew on things that are cool. Most teething infants are also soothed by the gentle, active massaging of their gums. So we developed the Water Massaging Teether, an easy to grasp teether that combines cooling comfort with gentle vibrations that are activated as soon as your teething baby bites down. At last, your teething baby can receive the best of two proven methods of relief all in one fun product! Multi-textured fin for a variety of comforting surfaces. Water-filled fin offers cooling massaging comfort. Gentle vibrations begin instantly when child bites down on fin. Sanitized drinking water inside for your peace of mind. 2-Ring handle is designed for two little hands to grasp. Lightweight so it's easy for baby to hold. Non-replaceable battery is sealed inside for safety. Conforms to ASTM Specification on Toy Safety F963. PVC-free. This product does not contain polyvinyl chloride or phthalates. CE Listed. Made in China to The First Years' quality specifications.