Dr. Browns Options bottles are the first convertible feeding bottles designed to grow with your baby. Use them with or without the vent system for flexibility as your child develops. The unique vent design creates vacuum-free feeding that helps reduce common feeding problems like colic, spit-up, burping, and gas. It also supports better digestion and helps preserve important vitamins in breast milk. The nipple venting creates a natural paced flow similar to other quality bottles. Each set includes six four-ounce bottles with Level One silicone nipples perfect for newborns through three months, plus a cleaning brush. These bottles are compatible with most breast pumps, completely BPA-free, and proudly made in the USA. Give your baby the comfort and health benefits of Dr. Browns Options.