FAST Tailpipe Mount 02 Sensor TestMade of stainless steel and convenient for quick oxygen sensor tests, this easy to use FAST kit slides into the tail pipe to prevent welding. The actual O2 sensor screws into the kit, which includes a rubber cover to prevent damage to polished exhaust tips. This kit allows you to temporarily install wideband O2 sensors into exhaust tail pipes without permanently modifying the exhaust system or welding anything! Clamps on and does not damage exhaust