I just read some interesting stuff that might be of interest to you. I was on a hunt to find out if the internal venting systems of Dr. Brown bottles were BPA and Polycarbonate free. I found out that they are! That applies to all Dr. Brown's. Also, I saw that people were buying the Gerber Clearview glass bottles and they say the internal venting system, cap and nipples from their Dr. Brown's fit in them. People were saying they had to use an exacto knife to trim the length of the valve (not sure I like that idea) but they said the short 4 ounce valves fit and work perfectly in the full size Gerber glass bottles! Do you have any 4 ounce Dr. Brown's? You may not have purchased any. I have two and rarely use them because she drinks more than 4 ounces. I may look for Gerber glass at Target and buy a couple so I can try it and get use these parts that I am otherwise not using.

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