The uniquely designed Dr. Brown?s Natural Flow? Options+? Level 4 Wide-Neck Nipple is a fast flow nipple, designed for babies who are more developed or prefer a quick flow. The breast-like shape encourages a proper latch for a more natural bottle feeding experience. Designed alongside medical professionals, the correctly contoured nipple shape and high-grade, soft silicone offer a more comfortable feeding experience and help to avoid nipple confusion. Perfect for switching from breast to bottle and back again!