This heavy duty animal control screen has a tamper proof bolt-on attachment method to prevent even the most bothersome animal pests, such as raccoons and opossums from gaining access to the chimney! Two types are available: Manufactured with stainless steel 18ga and Galvanized 18ga Painted Black (RC) or Stainless Steel (RS). The RC Galvanized Screens are made from heavy duty galvanized 18 gauge 5/8" mesh Painted Black. The base is 14 gauge galvanized steel. The RS Stainless Steel Screens are constructed with heavy 18 gauge stainless steel 5/8" mesh. The base is 16 gauge stainless steel. The Mesh Height for both is 6" tall from the top of the flue.