The DuraTech 8 Class A Chimney Pipe Wall Thimble adjusts from a minimum of 4 to a maximum of 10 wall thickness, and fits between standard wall studs. To accommodate thicker walls, the telescoping pieces can be extended up to 16 with a field-fabricated extension installed. Interior trim ring painted black. Must be installed with DuraTech chimney pipe horizontally through the wall and extend 6 into the room beyond the interior wall. (Black painted DuraTech is available). 6 and 8 stainless steel exterior trim available.Exterior Trim Dimensions: 16 x 16 Fuel Type: Coal, Gas, Oil, Wood Interior Trim Dimensions: 16 x 16 Material: Galvanized Steel Pipe Class: Class A Pipe Inside Diameter: 8 Pipe Shape: Round Style: Functional UL Listed: Yes Vent Construction: Double Wall Weight: 6.9
