Draft King CBO811 Round Slip In Black Galvanized Steel Single Flue Chimney Cap with Legs Welded onto the Cap, 10" Diameter For masonry chimneys only. Not for use with air-cooled metal chimney systems. Fits outside tile (inches): 9.5 to 10.5 Round. 24 gauge powder-coated galvanized Steel hood with scalloped corners and roll-formed edges, 18 gauge 3/4 inch 100% galvanized Steel expanded metal mesh. Outside mounting provides greater free air space. 7 year limited warranty