The NUK Smooth Flow™ Pro Anti-Colic Baby Bottle features an anti-colic venting system proven to reduce baby colic symptoms of gas, extensive crying, and reflux. The advanced venting system minimizes air bubbles in the milk so baby swallows less air, reducing spit-up and burping. The NUK Smooth Flow™ Pro Anti-Colic Bottle has fewer pieces than the leading anti-colic bottle*, so it's easier to prep, assemble, and clean. And because the nipple and collar is only one piece, there are no leaks, guaranteed. SafeTemp™ technology features a blue thermometer indicator that fades when milk is too hot and reappears when milk has cooled and is safe to drink. The newborn bottle's unique nipple design allows baby to control the flow of milk with their suction strength, delivering comfortable, colic-free feeding. Our Anti-Colic Baby Bottle is BPA-free and dishwasher-safe. *based on NPD Unit Sales L52 2021