The nipple only releases milk when baby is actively drinking Babies can drink, swallow and breathe using their natural rhythm, just like breastfeeding - making it easy to combine breastfeeding and bottle feeding This bottle has a unique nipple opening that only releases milk when baby is actively drinking - so when baby stops swallowing and breathing, the milk stops too The wide, soft and flexible nipple of the Avent bottle is designed to mimic the shape and feel of the breast, helping baby latch on and feed comfortably The anti-colic bottle value is designed to keep air out of your baby's tummy during feeding, to help reduce colic and discomfort The Philips Avent ergonomic baby bottle is easy to hold at any angle for maximum comfort while feeding - easy for both your hands, and little hands, to hold! Every baby feeds differently, and develops at their own pace