AirBake Natural Cake Pan with Cover, 13 x 9 in Air insulation prevents top sheet from overheating which prevents burning Micro-Dome technology decreases bake times by up to 15-percent 100-percent aluminum No rust promise 10 year warranty Baking pan made of 100 percent aluminum; insulated, break-resistant cover Decreases bake times by up to 15% over traditional insulated bakeware Insulated to prevent top sheet from overheating; no-rust promise 13 by 9 by 2-1/4 inches; dishwasher safe; safe with metal utensils Lifetime warranty