Super-Soft Silicone: The teats are made of high-grade silicone, ensuring they are soft and gentle on your baby's delicate mouth. Precision Cut: Dr. Brown's teats are precision cut to ensure optimal performance and flow of liquid, allowing your baby to feed comfortably. Internal Vent System: Dr. Brown's BPA Free bottle features a patented two-piece internal vent system that helps to reduce feeding problems like colic, burping, and wind. This vent system allows for vacuum-free feeding, similar to breastfeeding, by channeling air from the teat collar through the vent system to the back of the bottle. This prevents air from mixing with the breast milk or formula, minimizing oxidation and helping to maintain essential nutrients. Positive-Pressure Flow: The vent system creates positive-pressure flow, ensuring that the breast milk or formula flows freely without teat collapse. This allows babies to feed more comfortably without experiencing the discomfort of ingesting air bubbles. Reduction of Feeding Problems: By reducing the negative effects of a vacuum and preventing air ingestion, Dr. Brown's teats help to minimize common feeding problems such as colic, burping, and wind. The Dr. Brown's Narrow Neck Preemie Teats are designed to provide premature or small newborn babies with a comfortable and efficient feeding experience, helping to support their growth and development. (description exceeds maximum possible length)