InnoFlue Connector Rings seamlessly integrate with Centrotherm components, ensuring a joint fitting that prevents leaks and maintains airtight exhaust flow. Required in 2", 3" and 4" diameters by UL, InnoFlue Connector Rings are evaluated to the mechanical standard to meet/exceed all relevant tests. Made of galvanized metal, InnoFlue Connector Rings utilize a cantilever system to provide additional support at each fitting connect. InnoFlue Connector Rings are recommended in all diameter applications.