DSP5 Switch, Duramax | 2004.5 - 2005

The DSP5 Switch by Fish Tuning for your GM 6.6L Duramax is designed to work seamlessly with EFI Live Tuning on your LLY.  It allows you to change your tuning on-the-fly, offering greater flexibility. Please note that tuning is not included—you must have DSP5 tuning already installed to use this switch.