MagnaFlow's Hex Flanged Performance Exhaust Oxygen Sensor Plug 10044 built from high-quality stainless steel for maximum durability and corrosion resistance and a thread diameter of 18 x 1.5. Ideal for custom oxygen sensor installations it can also be used for exhausts downpipes headers and other setups. The MagnaFlow Hex Flanged Performance Exhaust Oxygen Sensor Plug 10044 is covered by a limited lifetime warranty.