my poor baby had a rough start, and after having to discontinue breast feeding and go to formula i went through a number of different bottles before chosing playtex ventaire advanced. the little guy was a huge spitter and very very gassy all the time, even after being burped a dozen times following a feeding and several times during. after switching to the playtex ventaire advanced bottle the gas and spit was greatly reduced. the bottles are bpa free and come in clear bottles with pleasant pastel colored rings. the bottle features a vent system bottom which is a silicone part inside a ring with...