I LOVE these food storage containers. The glass in itself is what sold me on the product many years ago when I first purchased a set. You don't have containers that are stained with the food you have stored in it (think spaghetti sauce stains). They heat up perfectly in the microwave. And I have never had an issue with the lids losing their grip. I loved my first set so much I recently decided to purchase two additional sets to add to my collection!!