Make sure your diesel is prepared to perform in the coldest conditions with aFe's DFS780 Fuel System Cold Weather Kit. The kit works with DFS780 and DFS780 PRO diesel fuel systems and easily plumbs into your engine's cooling system to warm the fuel to keep it from gelling in freezing temperatures. Heater hose not included. Note: The Heater Hose connecting the coolant spacer to the cooling system is not included but can be easily sourced.