Features:It helps reduce feeding problemsHelps digestion and helps to preserve vitamins.The teat venting creates a paced flowProvides a feeding experience similar to most teat-vented bottles.Options bottles fit most breast pumpsBPA-freeMade in the USA.Description:Dr Brown's Options : the market's first convertible bottle that can be used with or without the vent system . The New vent system is designed to grow with baby and we recommend using this system to experience all the health benefits of our bottle. It helps reduce feeding problems, helps digestion and helps to preserve vitamins. Some mums and dads find removing the vent a convinient option as their baby's feeding becomes more developed. The teat venting creates a paced flow, and provides a feeding experience similar to most teat-vented bottles. Options bottles fit most breast pumps , and are BPA-free and made in the USA.