Comfort Flame's Square Top Termination is designed for use with FMI wood burning fireplaces. Features double wall pipe with 8 inch inner and 12.375 inch outer diameters. Constructed of durable galvanized steel, these terminations are rust and corrosion resistant. All Direct Vent and Wood Burning products require venting to the outside of the home to achieve proper ventilation and firebox combustion. FMI Products offers a full assortment of venting components to properly vent the Direct Vent or Wood Burning fireplace. Features Use with FMI wood burning fireplace only by Superior Fireplace. Corrosion and rust resistant. Galvanized steel construction. Double wall wood burning pipe. 8 inner and 12.375 outer diameter.