Natural feeding system for babies switching between breast and bottle. A clinical study confirms that babies using these advanced bottles had less gas, spit-up, colic and other discomforts than with other leading bottles. Here's why: Breakthrough micro-channel vent technology Unlike ordinary bottles*, this one keeps air at the back of the bottle as baby drinks, so virtually no air mixes with the milk and gets into baby's tummy Reduces the negative effects of vacuum build-up, so baby controls the milk flow comfortably Angled bottle design helps prevent ear infections Promotes the semi-upright feeding position recommended by pediatricians to help prevent ear infections  Easy to clean All parts top-rack dishwasher-safe Removable top and bottom for easy cleaning Leak- and break-proof Compatible with Nursing Necessities breast pumps BPA *Other bottles - air vents through nipple, causing bubbles in liquid. Made in China Baby, Children & Toys , Feeding Essentials , Bottles & Nipples , Bottles