This bpa free bottle is proven to reduce colic and fussiness, especially at night. the unique valve integrated into the nipple flexes to allow air into the bottle, preventing vacuum build up, and preventing air into your baby's tummy. the extra soft silicone nipple is available in different flow rates for babies of all ages. with few parts, rounded edges and wide neck, the bottle is easy to clean thoroughly. ease of cleaning helps to ensure more hygienic, healthier feeding.