The containers are made with borosilicate glass, which can handle quick temperature changes without cracking.
Brad's Deals Editor Jim,
This OXO 14-Piece Freezer-to-Oven Serve and Store Set listed at $69.99, but you can get it for $49.13 during this sale at Jet.com. Shipping is free, and that's the best price we can find anywhere by about $6. The set includes baking dishes, lids, a loaf pan, and round snap containers. The containers are made with borosilicate glass, which doesn't crack with quick temperature changes. That means you can quickly from your freezer (or refrigerator) into an oven. Sales tax is charged in most states.