Level up to a faster nipple flow! Dr. Brown’s® Level 4 Narrow Nipple is our fastest flow nipple for babies 9m+. Dr. Brown’s uniquely designed Level 4 Narrow Nipple is a fast-flow nipple that works together with our internal vent system to help growing babies feed at their own pace. Each Level 4 Nipple 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 Level 4 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 Level 4 Nipple fits all Dr. Brown’s Narrow bottles. The suggested age range for the Level 4 Nipple is 9 months+, but baby’s preferred flow rate may vary. Dishwasher (top rack) and sterilizer safe. BPA free.