Mauviel Made In France M'heritage 150s 6527.01 0.4-Quart Butter Warmer with Stainless Steel Handle Mauviel's m'heritage collection is made of two traditional cooking materials: copper and stainless steel, (90-percent copper and 10-percent 18/10 stainless steel) Copper exterior offers superior control, heats evenly and much faster than other metals; stainless steel interior preserves the taste and nutritional qualities of foods and is easy to clean Cast stainless steel handles stay cool during use; m'heritage can be used on gas, electric, induction (with a disc), halogen, and in the oven Made in France and is guaranteed for life against any manufacturing defects