100% silicone beads (similar to pacifiers and nipples). Soft on babies gums and emerging teeth. No BPA, phthalates, cadmium, lead, metals. Easily cleaned with dish soap and water, also dishwasher safe. Necklaces have a breakaway clasp for added safety. Necklaces are a great sensory tool to help babies focus while nursing. Necklaces are approximately 30" long. Breakaway clasp for added safety. Adult Jewelry. Chewbeads Adult Necklaces are not a toy & are not intended to be worn by children.