The DVL 8 Inside Diameter Masonry Thimble with Slip Connector is a component that is used in a typical venting installation. Penetrates masonry chimney for connection of DuraBlack or DVL to DuraLiner. Adapter must be used to attach the connector pipe to the masonry thimble.UL ListedADA Compliant: No Collection: DVL Finish: Black Fuel Type: Wood Height: 14 Inside Diameter: 8 Length: 7-1 4 - 10 Material: Galvanized Steel Pipe Class: Stove Pipe Pipe Shape: Round Style: Contemporary Modern Vent Construction: Double Wall Weight: 4