Perfect for the food service industry, Schebler FyreGuard will put your fire safety concerns to rest. The prefabricated, double wall round grease ducts are designed and built for small, tight spaces, and is available in both 3” and 4” insulations. There is no need for field welding, secondary insulation or a fire-rated shaft. It is UL 1978 listed for grease duct and UL 2221 classified for zero-clearance to combustibles with a 2-hour fire rating. FyreGaurd is available with a 304 or 316 stainless inner liner and a standard 430 stainless steel outer jacket (other outer jacket materials available).