This has go to be the best food storage system available. The lids are secure and fit snug but they're easy to break the seal and open, unlike some other brands I've tried. The glass is the typical thick and quality glass you expect from Pyrex. The sizes are convenient for leftovers and cleanup is a breeze. I haven't had an issue with lid staining either so that's a huge plus in my book. I'm definitely going to buy more and add to my collection.