6" DuraVent DuraLiner Flat Round Stove Connector 6DLR-FCNR 6" DuraLiner Flat Round Stove Connector is used to connect insert to round DuraLiner pipe. Diameter: 6" Dimensions: 10 1/4" x 10 1/4" Height: 2" .016†304 stainless steel inner liner. Rigid relining pipe: double-walled with 304 stainless steel inner and galvalume outer. Factory insulated between inner and outer walls.