Glass and plastic lids make cooking, serving, and storing easy and convenient;Durable stoneware material designed for use in oven, microwave, refrigerator, and freezer;Corningware material resists chipping and cracking;Non-porous surface does not absorb food odors, flavors, or stains;20-Ounce mug weighs 1 pound upon shipping; a 1-Year warranty is available for this product