The uniquely designed Dr. BrownÕs Natural Flow¨ Options+ª Level 4 Wide-Neck Teat is a fast flow teat, designed for babies who are more developed or prefer a quick flow.ÊThe suggested age range for the Level 4 teat is 9 months+ but babyÕs preferred flow rate may vary.Ê The breast-like shape encourages a proper latch for a more natural bottle feeding experience. Designed alongside medical professionals, the correctly contoured teat shape and high-grade, soft silicone offer a more comfortable feeding experience and help to avoid teat confusion. Perfect for switching from breast to bottle and back again! Together with the anti-colic internal vent system, the Level 4 Wide-Neck Teat gives baby vacuum-free feeding that is clinically proven to reduce colic, decreases reflux, burping, and wind, better preserves nutrients, and aids in digestion for a good nightÕs sleep. While our bottle works best with the vent system, itÕs great to have options when babyÕs feeding develops. Just remove the vent and the feeding experience is similar to most teat-vented bottles. Fits Dr. BrownÕs¨ Options+ª Wide-Neck bottles. Dishwasher (top rack) and steriliser safe. BPA free.