Thank goodness for this bottle.  IT has been very helpful to me.  My first son is going to be 14 this month, I didn't have something like this and he suffered alot from gas.  I just had another baby, he is 2 months.  He really like the nipples.  He is able to burp with out a problem.  I have only had one time where he was gassy.

This is a great product, the price is about average, it does have a small cap that is a little hard to get clean sometimes, but it is worth a little work to get clean verses a gassy baby.