Built-in M18X1.5 catalytic converter, helps to checking engine lights. General model is suitable for most automobiles. Built in mini catalytic converter, avoid checking engine lights after modifing exhaustor or removing catalytic converter. Don't risk using extensions because they usually don't work. This is a real mini catalytic converter. Make ECU think an inventory catalytic converter is still installed, after removing the catalytic converter, it will see higher temperatures and greater unburned fuel flow. Size: Hexagonal 22 mm, length 55 mm. Inner diameter thread *1.5 Colour: silver Material: stainless steel Package Contents: 1 * Sensor Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.