Unlike other pumps that tug and pull the nipple, the Dr. Brown's Natural Flow pump works by using patented One-Way airflow in combination with a unique honeycomb liner that gently and rhythmically stimulates the nipple to increase Prolactin and Oxytocin production, which insures an increased milk supply, faster let-downs and a healthier baby. Dr. Brown's Natural Flow breast pump is the only pump to offer this combination for mom and baby.