The DVL 8 Double Wall Telescoping Length - 29 - 46 is a component that is used in a typical venting installation. Use for a two-piece installation from stove to ceiling support box or finishing collar. Available in 29- 46 and 40- 68 extensions. No cutting is required.Fuel Type: Wood Length: 68 Material: 26 Gauge Aluminized Steel Pipe Class: Stove Pipe Pipe Inside Diameter: 8 Pipe Shape: Round Style: Contemporary Modern UL Listed: Yes Vent Construction: Double Wall Weight: 16