Original orthodontic nipple reduces colic & promotes healthy oral development. Special design reduces colic: The NUK AirSystem vents the bottle, preventing vacuum build up - this allows baby to drink continuously, swallowing liquid instead of air. Original Orthodontic Nipple: Is the same orthodontic shape as NUK pacifiers, designed to fit baby's oral cavity.Promotes healthy oral development & reduces colic. Simulates & supports breastfeeding: The nipple is shaped like mother's breast during feeding. Studies show it simulates the breastfeeding experience. Supports switching between breast and bottle. 0+ months. Silicone. Slow flow.