The mother's breast changes its shape as she feeds her baby. It adapts to the baby's mouth, strengthens his jaw, palate, tongue and lips. The shape of the NUK teats adapts to the baby's mouth just like the mother's nipple during breastfeeding. NUK FIRST CHOICE teats systematically combine the anatomical benefits of the NUK shape with the sensation of being on the mother's breast. Get a feeding pattern very similar to breastfeeding. NUK Anatomical Anti-Colic Teats reduce the risk of colic in the baby caused by ingestion of air thanks to the NUK Air System ventilation system.