Don't take a chance on using an extension that often does not work. This is a real mini catalytic converter built into the unit. This O2 sensor fix contains a miniature catalytic converter inside and helps resolve the check engine light that appears after modifying your exhaust or removing your catalytic converter, and sometimes even when installing a high-flow catalytic converter. These modifications can trigger check engine lights with error codes such as P0420 (Catalyst System Efficiency Below Threshold Bank 1) and/or P0430 (Catalyst System Efficiency Below Threshold Bank 2). CEL Fix Check Engine Light Eliminator Adapter - O2 Sensor for automotive use. New and high quality. Type: O2 Oxygen Sensor Adapter Surface treatment: electro-nickel plating Thread: M18x1.5 Length: 58mm Function: check engine light fix Color: silver Material: metal Size: 58x16x25mm Package Contents: 1 x O2 Sensor Adapter Ext Note: The package includes only the items listed above. Other products are not included. Note: Lighting and display differences may cause slight variations in color between the image and the actual item. Measurement may vary by +/- 1-3cm.