Dr Brown’s Preemie Flow Narrow Teat is Dr Brown's slowest-flow Teat, great for Preemies, newborns, and breastfed babies! Dr Brown’s uniquely designed Preemie Flow Teat works together with the internal vent system to help babies feed at a pace that’s perfect for them. Each Preemie Flow Teat provides the same consistent flow rate, so both you and baby know exactly what to expect. Together with the anti-colic internal vent system, the Preemie 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.