This package includes the KESSv2 MASTER hardware and activations for DSG Transmissions, which support DQ200/250, DQ500 and DL501. KESSv2 allows you to read and write to the ECU by connecting the tool to the diagnostic port using the supplied connector. The MASTER version allows you to read the stock ECU file unencrypted; then once you have modified the file, you can flash the file back to the ECU with automatic checksum correction. The MASTER hardware gives you the flexibility to manage your own files.