Natursutten Baby Bottle Anti-Colic Double Valve for Anti-Colic Bottles & Natural Rubber Bottle Nipples - Colic & Gas Preventing Bottles Parts - 2 Pack

Really help keep air out of baby's bottle, which reduces gas.

I bought these with the slow flow naturautten nipple as it stated they have to be used together. Even with this little piece in the bottle the “slow flow” nipples were WAY too fast.

I bought this thinking it could fit on any standard neck bottle but I was completely wrong. I was wanting to use it along with preemie nipples for newborn puppies but they wouldn't fit any of the standard neck bottles I had. I love the idea that the base of this would cover the entire opening of the bottle so that milk could go straight to the one-way valve and stay in the nipple preventing the ingestion of air. Compared with 2 other similar products I own, the material is noticeably thinner but the other brands do not have the wide base so this one would've been my go-to product if it was the right size. I may cut it to size and use it anyways.

These things get lost down the garbage disposal So it’s imperative that you have some extras so that you can continue to keep your baby gas free! These worked perfectly with my bottles!