Philips Avent Natural Response baby bottle nipple lets babies control the pace of the milk, like they do when breastfeeding. The nipple's unique opening and tip only release milk when your baby actively drinks. When pausing to swallow and breathe no milk flows. Baby can drink, swallow, and breathe using their natural rhythm. Easily combine breast and bottle feeding with a wide breast-shaped nipple that mimics the soft feel of a breast. The nipple has a no-drip design which helps prevent lost milk from the tip. An anti-colic valve integrated into the nipple is designed to reduce colic and discomfort by sending air away from your baby's tummy. Every baby feeds differently and develops at their own pace. We’ve designed a range of flow rates so you can find the perfect one for your baby and personalize your bottle. We have moved to a pace-based flow navigation system. The Natural Response nipples come in flow rates 1-5, to keep up with your baby's development. Start with the nipple that comes with the bottle. Try a lower flow if milk is leaking from baby’s mouth or baby is gulping. Try a higher flow if baby is playing with the nipple instead of drinking or seems frustrated. It is totally natural for your baby to take 2-3 tries to get milk flowing from a new feeding bottle. Use Philips Avent Natural baby bottles only with Philips Avent Natural Response nipples. Philips reduced the carbon footprint by switching nipple packs to 100% responsibly sourced paper packaging. The result is 300 tons less plastic per year¹ and 88% less fossil fuel use², minimizing the impact on the planet. ¹ Based on global annual sales of nipple packs, using net weight of the plastic nipple case ² Compared to previous packaging​