Product Description 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 burping and wind, preserves nutrients, and aids in digestion for a good night's sleep. While our bottle works best with the vent system, it's great to have options when baby's feeding develops. Just remove the vent and the feeding experience is similar to most teat-vented bottles. The uniquely designed Dr Brown's Natural Flow Options+ Level 4 Wide-Neck Teat is a fast flow teat, designed for babies who are more developed or prefer a quick flow. The suggested age range for the Level 4 teat is 9 months+ but baby's preferred flow rate may vary. The contoured breast-like shape encourages a proper latch for a more natural bottle-feeding experience. Designed alongside medical professionals, the correctly contoured breast shape and high-grade, soft silicone offer a more comfortable feeding experience and help to avoid nipple/teat confusion. Perfect for switching from breast to bottle and back again! Designed to fit Dr Brown's Options+ Wide-Neck bottles only. Dishwasher (top rack) and steriliser safe. BPA free.