You and your little one will enjoy bottle-feeding with the Dr. Brown's 8-Ounce Baby Bottles 3-Pack in the Blue style, which allows air to channel from the nipple collar to the back of the bottle to help prevent bubbles and feeding problems such as colic, spit-up, burping and gas. Two-piece internal vents create positive airflow for vacuum-free feeding without nipple collapse. Air never mixes with the breast milk or formula, helping to prevent oxidation and maintain essential vitamins. The bottles are free from BPA, PVC, lead and phthalates.