Heat tamers are made of heavyweight steel to promote uniform and controlled heating on electric or gas stoves. It creates a flat cooking surface giving the old stovetop a new look. Spreads heat evenly under pots, resists spills, boil-overs,and wipes clean. Fits most electric-coil or gas burners. Proudly made in the USA by Nordic Ware. Not for use on ceramic or glass top stoves.