Lennox 31W19 Flue Transition Freon Superior Material Integrity: Components are Superior Material Integrity: Components are rated for standard HVACR synthetic oils and high pressure refrigerants to prevent premature elastomer degradation the 667285R is the factory designated successor to the 667285 and is compatible with various Nordyne brand air handlers and furnace assemblies where that part number was original equipment Direct OEM Fit: Specifically engineered as a Lennox furnace part to ensure seamless integration with existing exhaust manifold configurations without field modifications Can I use high temp silicone to seal a cracked transition instead of replacing it