Dr. Brown s Natural Flow baby bottles are the only bottles designed by a doctor to help reduce colic, spit-up, burping and gas. Dr. Brown s bottles feature the patented internal vent system, which creates positive-pressure just like breastfeeding. This fully-vented bottle design produces a more comfortable feeding by eliminating the vacuum and excess air ingestion. It s the venting system your baby deserves, in a choice of bottles to fit your lifestyle. Dr. Brown s bottles are also easy to clean and dishwasher safe. Includes 2 Standard 7-ounce Dr. Brown s Natural Flow baby bottles with Level-One nipples. Made in USA.