This is the factory European immobiliser unit for higher output engines. A very large percentage of European Mk3 GTI and TDI engines use this setup.
In a engine swap situation you can have the immobilizer removed by reprogramming, or you can run this option which will switch it off when power is switched on and the key is next to the reader.
It is a simple four wire install, and you can choose between installing the grain-of-rice chip contained in the donor key into your own vehicles key, or simply leaving it connected to the reader permanently (or get creative and make it an additional removal hidden key if you're concerned about hot wiring!).
These complete modules are $55 when purchased with a ECU, or $80 without. If you would like to purchase without a ECU please email us at firstname.lastname@example.org
NB: There is a later version, which is fundamentally identical except it also has a 5th wire which is red and goes to the 30/permanent power. Either unit may be used and either may be supplied.