Classy Feeding bottle comes with variable flow teat. Silicone teat made from medical grade silicone. The bottle has a hood and a disc to place in the neck of the bottle, to prevent leakage during transportation. PUR silicone nipples are passes repeated post production testing and prolinged curing processes, have almost zeroed volatile substances on nipple distributed which are safe for your baby. PUR Silicone nipple is Volatile safe.