AirBake brand has always been "The Original Insulated Bakeware".AirBake continues to provide the best baking results every time.AirBake Nonstick provides an overall enhanced baking performance with its insulated aluminium sheets and micro-dome technology to decrease bake times by up to 15% over traditional insulated bakeware.Two heavyweight aluminium steel sheets with a nonstick surface 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.Insulated bakeware means cookies won't burn and the nonstick surface means clean-up is a breeze.Set includes medium cookie sheet 36cm x 30cm and Large cookie sheet 41cm x 36cm