Made of a revolutionary combination of a tempered borosilicate glass interior with a ceramic exterior for more consistent performance. Full Circle SmartGlass Casserole Pans are safe from oven to table to freezer. Have leftovers? Not a problem! Full Circle Casserole Pans include a handled lid which locks in moisture to keep food fresh longer. These pans are also microwave, freezer and dishwasher safe. While most tops out at 350ºF/176ºC, all Smartglass pieces can go up to 450ºF/232ºC, which promotes the nutty caramelization that helps make your favorite dishes so special. And SmartGlass heats slowly, which means more even and consistent cooking.