Customer Rating: Summary: Wonderful product Comment: I've had some of these for a long time. My daughter-in-law saw them and wanted them for Christmas. I bought half gallon and quart jars to go along with these for gifts for them both. They make great items for storage as well as in the fridge and freezer. Will go straight to microwave. I highly recommend these. Customer Rating: Summary: Good product, good price and fast shipping. Comment: Really good plastic caps. Great price and really fast shipping. Good company to deal with. Customer Rating: Summary: Great product Comment: I bought some of these caps not long ago when I just ran upon them. I had been looking for a plastic cap with a good seal to use on canning jars that I use and reuse. I especially needed plastic because I make kefir in Ball canning jars and kefir is very acidic causing metal caps to rust. I also needed to be able to securely shake the jar before use without leakage. These caps are well-suited for both purposes. They are also good for use on home-canned pickles, mayonnaise jars, etc, which also are best with plastic due to acidity. Of course, you cannot can foods using these caps, but they can be placed on the jars after canning, or after making jams and jellies, for storage. I recommend these specific caps because I have used them and they serve the purpose well for which they are sold.