Product Lenght is 45mm long On ODB-II vehicles (96+), the ECU has two O2 sensors for diagnostic purposes. The first O2 sensor is located before the Catalytic Converter. This O2 sensor is responsible for all the Air/Fuel tuning and is imperative to the operation of the vehicle. The second O2 sensor is located after the Catalytic Converter. The whole purpose of this O2 sensor is to ensure that there is a functioning catalytic converter in the system. The way it can detect this is to make sure that there is a difference in exhaust gasses between the first O2 sensor and the second. If the same exhaust reading is detected, then the ECU knows that there is either a damaged Catalytic Converter or no Catalytic Converter at all. The ECU will then trigger a Check-Engine Light. On some instances, the vehicle will be thrown into a Null mode where the vehicle will not go over a certain speed and will be basically rendered useless. This mechanical O2 fix is basically a way to space out the O2 sensor so that it still reads SOME exhaust gasses but it removes the O2 sensor from the direct flow of the gasses as to make the ECU believe there is a restriction in the exhaust gasses such as by a Catalyst. There is NO GUARANTEE that this product will work on your specific application. There are always mixed results depending upon the layout of the exhaust system and the tuning of the ECU, however, this mechanical O2 fix is well known for eliminating most CEL s caused by an O2 Sensor. NOTE: There is no guarantee that this will eliminate your O2 sensor CEL. Some vehicles will need their ECU reset if the CEL is triggered before hand. - O2 Sensor Thread Pitch: M18x1.50 NOTE: All Exhaust and Suspension products are deemed for off-road use only -- please check local laws regarding the modification of the exhaust systems by checking the vehicle code for your state. Many states are more stringent on exhaust modification laws and to pass SMOG. Please check your local laws. Package Included: 20 PACK 45MM O2 OXYGEN SENSOR EXTENDER NOTE: If you have any questions, please feel free to contact us. We will respond you as soon as possible. We maintain high standards of excellence five stars and strive for 100% customer satisfaction Positive Feedback is very important to us. We request that you contact us immediately before you give us neutral or negative feedback, we make sure we would suply best service for your customers.Contact Customer Services