BPA free. Trusted brand for 50+ years. The only bottle with an Orthodontic Nipple. Helps promote healthy oral development. Supports easy transition between breast and bottle. Hole placement aids digestion. Helps reduce colic with NUK Air system. Easy latch on with extra wide base. Special design helps reduce colic. The NUK Air System vents the bottle, preventing vacuum build up - this allows baby to drink continuously, swallowing liquid instead of air. Available in slow, medium & fast flow. Simulates & supports breastfeeding. The nipple is shaped like mom's during breastfeeding. Supports switching between breast and bottle. All NUK Orthodontic bottle system products are dishwasher-safe, top rack only. Instructions for use and care are enclosed. NUK Orthodontic Nipples have a more advanced design than standard round nipples. Feeding Hole Against Palate: Allows milk to mix with saliva and aid digestion. Angled Top: Reinforces correct tongue positioning. Hourglass Shape: Allows lips to close properly, minimizing air intake. Asymmetrical Design: Encourages proper jaw positioning. Extra-Wide Nipple Base: Mimics the shape of mother's breast. NUK Air System: Vent helps reduce colic and prevent nipple collapse. Mix n match. The NUK Orthodontic System is a line of products with coordinating designs and interchangeable parts that promote healthy oral development as your baby grows. 5 oz & 10 oz bottles. Slow, medium & fast flow silicone nipples. Orthodontic pacifiers. For 50+ years, moms have trusted NUK products to help them nurture their babies best. Assembled in USA with parts made in USA and Germany.