This is the PK Tensioner bracket only for cars that do not run the Air/Smog Pump.
PK Tensioner or PKT is a bracket designed to replace the existing de-tensioning system on the 928. The bracket allows the addition of an automatic tensioning system from a current Audi. The complete system, when fitted, keeps the timing belt at the right tension at all times unlike the original. There is also no need to re-check the tension after 2000 miles, every year or fill the tensioner with oil (the original system is known to leak).
The PKT is used on thousands of cars Worldwide and is highly recommended.
As the original tensioner is also the pivot point for your air/smog pump you need to choose the bracket suitable for your installation. If you are keeping your air/smog pump on your car choose with air pump if not choose without.