AirBake Natural Cookie Sheet, 20 x 15.5 in Baking Pan - New Description: AirBake brand has always been "The Original Insulated Bakeware". AirBake continues to provide the best baking results every time. Made of 100-percent aluminum, AirBake Natural provides an overall enhanced baking performance with its insulated aluminum sheets and micro-dome technology to decrease bake times by up to 15% over traditional insulated bakeware. Two heavyweight aluminum sheets surround a layer of air. The air reduces the temperature of the metal that comes in contact with the food. The bottom sheet blocks the direct oven heat while the layer of air acts as an insulator preventing the top sheet from overheating. This means better browning, no burning, and moister baked goods. Key Features: - 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 - 100% aluminum construction.