24-gauge single-piece galvanized steel hood. 18-gauge 3/4" expanded galvanized steel mesh. Black powder-coated paint finish. Stainless steel mounting brackets. Quick and easy installation (with only a screwdriver). Keeps out birds, squirrels, leaves, and debris. Protects flue from moisture. 1 cap fits several flue tile sizes: 8" x 8", 9" x 9", 8" x 12", 9" x 13", 12" x 12", 13" x 13", 8" Round OD (outside diameter), 10" Round OD, 12" Round OD