This plumbing kit includes the components needed to install an exhaust back pressure sensor (the sensor is available separately - part number 554-102). This type of sensor is often used with data acquisition, or EFI systems to monitor the exhaust back pressure just prior to the turbo. The exhaust heat and engine vibration are tough on the sensor, so it is mounted remotely and isolated by the stainless hardline & flexible Speed-Flex hose assembly. This kit includes: weld bung, pre-made stainless hardline, Speed-Flex hose assembly, sensor mounting clamp, adapters & hardware.