B5.5 Passats have a different glow plug system than other TDIs. They have four individual wires instead of an intact harness. This kit includes four wires and glow plugs - your choice of 5V steel or 7V ceramic plugs.
It is vital that you match the voltage of replacement glow plugs with those that are in the car. The BHW came with 7V plugs from the factory, however, a recall changed them to 5v. A second, later, recall changed back to 7V. The result is that there is a mixed installation of 5V and 7V plugs in the Passat BHW. You must determine your glow plug type, the best way is to remove a plug and read the markings on the sheath of the plug.
Switching to steel glow plugs requires an ECU re-flash. Your local VW dealer may be able to perform this service, and there are tuners who can also re-flash your ECU for the steel plugs.