Mauviel Copper 4-3/4-Inch Double Boiler Commercial quality copper double boiler, measures 4-3/4 inches in diameter Exterior made of shiny copper for excellent conductivity and precise conrol of heat Tin-lined bottom pan brings water to a gentle simmer beneath the heavy porcelain insert Solid bronze handles riveted to body of pan for durability; hole for hanging Hand washing recommended; polish exterior with copper-safe cleanser; limited lifetime warranty