Happy Feeding Options; Use With or Without Vent! Reduces Colic Spit Up, Burping & Gas Anti-Colic Vent System - Designed to Grow with Baby BPA Free Proven to Help Preserve Bottle Milk Nutrients* Vacuum-Free Feeding Helps Digestion Full-Vented Botte Design Internal Vent System and Silicone Nipple Work Together We recommend using the vent system to experience all the health benefits of our bottle: Helps reduce feeding problems. Helps preserve vitamins. Helps digestion. Vent and nipple create vacuum-free feeding. Some moms and dads find removing the vent is a convenient option as their baby's feeding becomes more developed: Provides a feeding experience similar to most nipple-vented bottles. Nipples venting creates a paced flow. Contents 1 - 5 oz/150 ml Glass Wide-Neck baby bottle. 1 - Level 1 silicone nipple. 1 - Cleaning Brush. Instructions *Per a university study.