This threaded tank adapter features a retainer ring molded into each fitting to prevent the sealing gasket from expanding or sliding out of position under compression. The bearing washer insures even compression on the gasket and promotes sealing. Made out of a durable Santoprene thermoplastic rubber, this adapter comes with fitting compression nuts that have a specially designed cross-section to prevent distortion under load. | Ace Roto-Mold Threaded Tank Adapter | Size 1-1/4"