This baby bottle bundle from Dr. Brown's includes their 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 comes with 8oz bottles in a pink floral design and Level 1 slow flow nipples, while the 2-pack features a squirrel and goat print design on 8oz bottles with Level 1 slow flow nipples. Both provide vacuum-free feeding that closely mimics breastfeeding, allowing babies to feed at their own pace. The anti-colic vent system also helps preserve nutrients and aids digestion for better sleep. The breast-like nipple shape supports proper latching and eases switching between breast and bottle. As babies grow, the internal vent can be removed without introducing a new bottle. These narrow bottles are sustainable, made to nourish through all feeding stages, and BPA-free. Dishwasher safe on top rack. Dr. Brown's collaborates with Plastic Bank to prevent ocean plastic. Together these products provide a complete anti-colic bottle feeding system with cute designs that babies will love and options to suit different needs.