
I bought these bottles as my son suffered from colic, they were initially great and really helped with the colic. I don't know whether it was that he was on thick milk or whether it is a design fault (I bought 6 bottles and the following problem happened with all 6) but within about 7 weeks the bottom silicone wheel that goes into the milk kept slipping off, which rendered the bottles useless. Having contacted Tommee Tippee they were happy to replace or refund. The variable flow teats were great though and my son really found them to his liking.
the best all round anti colic bottle we found and my word did we try a few! This one is easier to wash, assemble and is more robust than the others that we tried with the vented tube through the middle