This Doorbell Ringer is cast in solid brass. Brass and bronze are copper-based alloys. The yellow brass alloy used in many of Michael's designs contains 70% copper and produces a warm, traditional brass look. Red bronze contains almost 85% copper. This additional copper content gives the bronze alloy its rich, reddish undertone. The mirrored finish of polished brass and polished bronze is achieved through varying degrees of sanding and buffing. Michael uses these techniques to highlight or accent the raised areas on a piece. The sand mold in our casting process can only be used once making each Doorbell Ringer truly unique. All Michael Healy Products are coated with a protective finish and carry Michael's signature confirming the authenticity and quality craftsmanship. They are also easy to install.