This set is an option to the AFR Tuning Monitor. It allows you to install a pair of wide band sensors on all exhausts where it is not possible to simply replace the installed O2 sensors (M18 thread).The set contains a powerful double pump, which ensures high accuracy and measurement speed of the actual AFR in each cylinder. The pump is powered by a 12V supply and can therefore also be used for road testing. An open pipe adapter is available to extract undiluted exhaust gas farther up the pipe.