This is the set of four copper diffuser plates that add the superior cooking abilities of copper to any flat bottom steel, cast iron, or aluminum cookware. The 2.6mm-thick, 8" square copper diffusers are placed over a stove burner and transfer even, steady heat to any pot or pan for superior cooking results. The same material used to make professional cookware, copper conducts heat 70% more efficiently than the aluminum inside most high-end cookware and is preferred by chefs for its superior food-browning ability. Unlike cast iron or stainless steel pans that produce hot and cold spots, copper enables steady simmering of cream-based soups, stews, or a demi-glace without scalding. The copper will develop a natural patina with shades of blue, red, and orange if left untreated or its original color can be restored with widely available metal cleaners. For use on gas or electric stoves with pots or pans up to 8" in diameter. Not for use with induction stoves. 8" W x 8" L x 1/8" H. (2 1/2 lbs.)