Draft Hood ConnectorA transition fitting for connecting double wall Metalbestos pipe to the single wall flue collar or draft hood outlet of the appliance. Flexible shank can be shaped to fit oval outlets. 4-1/2 IN length.No. 3RV-DHC: 3 INNo. 4RV-DHC: 4 INNo. 5RV-DHC: 5 INNo. 6RV-DHC: 6 IN