If you plan on running the Evans High-Performance Waterless Coolant, then you will need to prep your engine to get rid of any residual water or coolant from your system. This is the Evans Cooling Prep Fluid designed to flush out any remaining coolant from your system just before you add the high-performance waterless coolant.
Note that this is not a form of coolant and shouldn't be used as coolant. It is inteded for flushing purposes only.
Sold as a gallon.