Dr. Brown's Newborn narrow nipple is the "just right" Flow for some newborns, breastfed babies, and babies with feeding difficulties. Faster than our Preemie flow nipple but slower than our level 1 nipple, brand new babies and developing babies with feeding difficulties may find the newborn nipple to be a happy middle ground! The newborn nipple also offers a more gradual transition for breastfed babies who have graduated from Preemie flow but are not quite ready for level 1. It's also great for any baby who simply prefers a slower flow! Each newborn nipple provides the same consistent flow rate, so both you and baby know exactly what to expect. Together with the Dr. Brown's Anti-colic internal vent system, The newborn nipple offers vacuum-free feeding that is clinically proven to reduce colic, decreases spit-up, burping and gas, better preserves nutrients, and aids in digestion for a good night's sleep. Made of super-soft, high-grade silicone, the newborn nipple fits all Dr. Brown's narrow bottles. Every baby has their own preferred flow rate and is not necessarily a reflection of their age or size. Dishwasher (top rack) and sterilizer safe. Bpa free.