Product DescriptionDr. Brown's Standard Bottle, Preemie, 2 Ounce, 2-PackFrom the ManufacturerDr. Brown's Natural Flow baby bottle was invented by a doctor and tested on his own children when they were babies, so you can rest assured that this product is as safe as it is effective. This revolutionary baby bottle features a patented "no vacuum" design. It helps colicky babies settle down/sleep and reduces colic, spit-up, burping and gas. This also helps to prevent fluid in the ear/no vacuum. It is easy to clean, and dishwasher safe. Preemie-flow nipple limits the amount of milk and formula for a comfortable feeding pace | Positive-pressure design eliminates air bubbles and vacuum | Patented internal vent system helps lower instances of colic, spit-up, burping and gas Preemie-flow nipple limits the amount of milk and formula for a comfortable feeding pace | Positive-pressure design eliminates air bubbles and vacuum | Patented internal vent system helps lower instances of colic, spit-up, burping and gas Preemie-flow nipple limits the amount of milk and formula for a comfortable feeding pace | Positive-pressure design eliminates air bubbles and vacuum | Patented internal vent system helps lower instances of colic, spit-up, burping and gas Preemie-flow nipple limits the amount of milk and formula for a comfortable feeding pace | Positive-pressure design eliminates air bubbles and vacuum | Patented internal vent system helps lower instances of colic, spit-up, burping and gas