The natural teat adapts to your baby's natural sucking rhythm, making it easier to switch between breastfeeding and bottle feeding. The teat has a unique opening that only releases milk when baby is actively drinking. When he pauses to swallow and breathe, milk flow also stops to prevent milk loss, whether you're at home or on the go. The large, soft and flexible nipple is designed to mimic the shape and feel of a breast, which helps baby latch on and helps you feed comfortably. The anti-colic valve is designed so that air does not enter the baby's belly during feeding to reduce colic and discomfort. Each baby feeds differently and develops at their own pace. We have designed a range of flow rates (0m+, 1m+, 3m+, 6m+ and 9m+), so you can find the one that best suits your baby and personalize your bottle. All natural pacifiers are made of soft silicone. Wide neck makes filling and cleaning easy. The few parts allow for quick and easy assembly. The ergonomic bottle is easy to hold at any angle to provide maximum comfort while drinking. It's easy to hold in your and your baby's hands. Philips Avent natural bottles and teats are made of BPA-free* materials. Features -Includes 2x 9oz bottle -Easy switching between breast and bottle feeding -Anti-drip teat prevents spillage and loss of milk -Air is kept away from your baby's tummy to reduce colic and discomfort -Bottle is BPA free -Easy to use, clean and assemble