This baby bottle bundle includes Dr. Brown's Natural Flow Anti-Colic Options+ Narrow Baby Bottles that feature an internal vent system clinically proven to reduce colic by decreasing spit-up, burping and gas. The 4-pack contains 8oz bottles in a blue nature design and the 2-pack contains 8oz bottles in a squirrel and goat print, both with Level 1 Slow Flow nipples designed for 0m+ babies. The anti-colic system provides a vacuum-free feeding experience closest to breastfeeding while the consistent flow rate silicone nipples allow baby to feed at their own pace. The vent system also helps preserve nutrients and aids digestion. The breast-like nipple shape encourages proper latching for a natural transition between breast and bottle feeding. As baby grows, the internal vent can be removed without needing to switch bottles. Both sets of BPA-free narrow bottles come in cute designs and are sustainable, made to nourish through all feeding stages and recyclable. Dr. Brown's also collaborates with Plastic Bank to prevent ocean plastic. With clinically-proven anti-colic technology, a natural feeding experience, recyclable and sustainably-made materials, and adorable patterns, this bundle provides the essential bottles and accessories to support your baby's developing feeding journey.