Features 1、The oxygen sensor plug is made of premium stainless steel material, so it's very easy to weld. 2、The size is M18 x 1.5, which fits most standard oxygen sensors. And the recessed step makes it easier to weld flush with the surface. 3、Designed to add oxygen sensors wherever you need it. Very suitable for custom exhaust devices, headers, down pipes, etc. 4、Easy to install, just drill a hole and solder it. And be sure to use a little anti‑sticking agent on the plugs when using it. 5、Threaded design guarantees firm connection, and the sturdy structure ensures great durability for long-term use. Specification Item Type: Oxygen Sensor Plug Model: M18 x 1.5 Product Material: Stainless Steel Application: Car modification parts, welding parts. Colour: Silver Package List 1 x Plug 1 x Nut