Dr. Brown's - Wide Neck Glass Bottle. Helps reduce feeding problems. Bottles are known to reduce colic, reflux, burping and gasFeatures. -Clinically proven reduction in colic -Reduces burping, belching and gas -Better preserves nutrients in breast milk and formula -Helps digestion for a good night's sleep -Provides flow that supports breastfeeding -Suitable for dishwasher (top rack) and sterilizer. Internal air passage system -Air enters the neck of the bottle and passes directly through the internal air passage system -Air passes through the end of the bottle, through the tube, bypassing the milk. -The air system prevents air from entering the milk, vacuum pressure and nipple rupture -The infant feeds comfortably as the milk flows freely, as in breastfeeding.