Clinically Proven: less fussing especially at night (At 2 weeks of age babies fed with an Avent Bottle showed a trend to less fussing than babies fed with another leading bottle). Less colic (At 2 weeks of age babies fed with an Avent Bottle showed a trend to less colic than babies fed with a conventional bottle). No. 1 for moms worldwide. BPA free. Clinically proven to reduce colic (At 2 weeks of age babies fed with an Avent Bottle showed a trend to less colic than babies fed with a conventional bottle) and fussing, especially at night (At 2 weeks of age babies fed with an Avent Bottle showed a trend to less fussing than babies fed with another leading bottle): Sleep and nutrition are vital to your baby's health and happiness. Fussing (Unsettled and irritable behavior) is by far the most commonly known crying behavior in babies. Clinical studies show that the Avent Bottle significantly reduces colic (At 2 weeks of age babies fed with an Avent Bottle showed a trend to less colic than babies fed with a conventional bottle) and fussing (At 2 weeks of age babies fed with an Avent Bottle showed a trend to less fussing than babies fed with another leading bottle). Fussing is reduced especially at night (At 2 weeks of age babies fed with an Avent Bottle showed a trend to less fussing than babies fed with another leading bottle). Anti-Colic System with Adapter Ring: The two piece anti-colic system consists of the Avent Nipple and adapter ring. The adapter ring is an essential part of the bottle design and must always be used. As your baby feeds, the unique skirt on the Avent Nipple flexes to allow air into the bottle instead of your baby's tummy. Like natural breastfeeding your baby controls the milk flow. BPA-Free Bottle: This BPA-free bottle (0% Bisphenol-A) is made from PP (Polypropylene). To fit your baby's growing needs - This pack contains a nipple with two holes. Made in England.