5” - 8” Diameters - Designed for appliances that are tested and listed for use with a 2100°F HT chimney system, such as wood stoves, fireplaces, furnaces, boilers, ranges, water heaters, or other appliances fueled by wood, oil, coal, or gas. Available in stainless steel (5"-8" SS) or galvalume (6"-8" GA) outer casing and stainless steel inner wall with twist-lock connections. DuraTech 24”, 36”, 48”, and 60” chimney pipe available with additional protective carton filler (CF) for shipping.