Le Creuset Stoneware Tea Mug, 14-Ounce, Hibiscus High-quality exterior enamel protects against metal marks and other damage Hard-wearing, impermeable finish fired at temperatures as high as 2192f is safe for cutting on with knives Unmatched thermal resistance from -65f to 500f safe for the freezer, microwave, oven, broiler and dishwasher Less than 1% porosity, blocking moisture absorption which can lead to cracking, crazing and rippling along the interior A perfectly color-matched palette of bold, consistent tones for easy mixing and matching with other le cresset products