I'm not sure if this is the right forum to put this in or not. But here goes anyway. What warrants an EUC? This confuses me as I see M35s need them but not the bigger M939 series trucks, as I see them it seems very haphazard in their application. I see the same thing on the HEMTT rear units, tow/recovery unit not needing one but the basic flatbed units requiring them. This just seems crazy to me.