Thunder Heart Performance Thundermax ECM with Integral Auto Tune System 309-361 ThunderMax ECM with Auto Tune module mounts conveniently in place of the factory ECM and plugs in to the existing harness Utilizes wide band O2 sensors and works as a closed-loop control system to continuously self-adjust and properly tune the motorcycles air/fuel ratio for all riding conditions Easy installation: replace the factory ECM, install new O2 sensors and harness, load the correct map for your bike, and ride Includes ThunderMax ECM with Auto-Tune Module, plug-in harness and two wide-band sensors, TMax software and communication USB cable, Quick-Start Easy Install and Comprehensive Users Manual, technical support and free software and updates Hundreds of maps available to download for your bike.