NorthStock, Inc. carries stainless steel category III and galvanized double wall type B vent kits for gas fired unit heaters. Vent kits are available in 3, 5 or 10 Ft. lengths, and can be ordered for sidewall or roof venting. Consult with a qualified installer to select the proper kit for your application. All kits are sold as-is, kit customizations and partial returns of unused pieces are not allowed.