I dropped once they didnt break easy to clean break down enough for me to get into the little spots and easy to store and no fo...  Read More

I dropped once they didnt break easy to clean break down enough for me to get into the little spots and easy to store and no foul spell over time like plastic bottles  Read Less

These are tricky to figure out, and I had to buy another set when the first set was stripped after ~5 months of use and started...  Read More

These are tricky to figure out, and I had to buy another set when the first set was stripped after ~5 months of use and started leaking where the white ring tightens because they wouldn't seal right. The white ring doesn't have a stop to it, so you can keep tightening them until they pop off the other side. There were no directions explaining this, but they need to be turned only until the they stop naturally without pressure, and presumably the glass will expand when it is heated up and make the seal tight enough not to leak. They have not leaked when I have done this. Because you can keep turning it though, there is a tendency to think, tighter is better, and turn with pressure so it is _really_ tight. This will strip the rings so they won't seal correctly after awhile and will need to be thrown out. My people at daycare continue to do this even after I figured it out and explained to them how it works. Also, it ticked me off that Philips Avent had NO replacement rings and was out of stock (indefinitely) on every model of replacement ring they had, so I had to buy all new bottles which is extremely wasteful as the bottles and nipples are useless once the rings are bad. Still, I have to give the product 4 stars and blame user error because they really are nice bottles if they are used correctly, and there aren't that many glass bottles on the market.  Read Less