Flush Mechanical Cleanout Repair Plug 3-1/2"Mfr #: 83689 Designed for use on cast iron cleanout fittings where the threads are worn or stripped Rubber gasket seals behind threads Proplus Flush Mechanical Cleanout Repair Plug, 3 1 2 In The country of origin is United States The first cleanout repair plug the really works! Holds up to 50 feet of backpressure! Seals air tight! (Does not rely on threads to seal.) Back pressure actually increases sealing ability! Completely flush inside and out!