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. This can trigger check engine lights with error codes such as P0420 (System Efficiency Threshold Bank 1) and/or P0430. 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: Lighting and display settings may cause slight variations in color between the image and the actual item. Measurement may vary by +/- 1-3cm.