The Airtronic D2/D4 Fuel Standpipe is an optional part for use in motorhomes when installing an Eberspacher Diesel Heater. They are only necessary when you want to draw fuel from a motorhome diesel fuel tank to power your air heater, and CANNOT tap into your existing fuel line.
A replacement fuel standpipe to suit the Airtronic Diesel Heaters. This is an optional part and isn't required to access your existing fuel line.
If you can tap into your existing fuel line or are using a separate diesel fuel tank (not the same one your vehicle runs off), you don't need to purchase one of these.