Parents have come to rely on Dr. Brown's bottles because of the health benefits for baby. This 3-bottle deluxe wide-neck bottle starter kit includes One 8-ounce wide-neck bottle, two 4 ounce wide-neck bottles, two extra level-2 replacement nipples, 2 extra Y-Cut nipples and a stainless steel cleaning brush. They feature the same patented internal vent system that helps reduce feeding problems like colic, spit-up, burping and gas. The positive-pressure design mimics breastfeeding and is ideal for breast milk and formula alike.