Bottle feed your baby with confidence, using the Philips Avent Natural Response 9 oz./4 oz. baby bottle set. The Natural Response nipple is designed to let the baby control the flow, just like they would when breastfeeding. These handy bottles are BPA-free, so you can rest easy knowing they are made from safe, quality materials. | Philips Avent Natural Response 9 oz./ 4 oz. Baby Bottle Set - 5 Pack