The Dr. Browns Glass Natural Flow Baby Bottles are a set of three 5 ounce wide-neck bottles made of thick glass. These bottles feature a wide-neck nipple with an anti-colic design, suitable from birth. The clear bottles are dishwasher, sterilizer, and scratch resistant for convenience. With a consistent flow nipple made of silicone, these bottles are designed for easy feeding and are manufactured in the United States by the trusted brand Dr. Brown's.