This is a Cambelt Idler pulley (below the Main Tensioner) for the V6 tdi Engines with the following engine Codes AFB AKN BDG BCZ BGH & BGJ for the following cars:

Audi

A4 & Quattro   1994 - 2008
A6 &      "           1998 - 2005
A6 Allroad          2000 - 2005
A8 & Quattro    1999 - 2007
A4 S4 Cabrio     2003 - 2006

Volkswagen 

Passat   1997 - 2005
Phaeton  2002 - 2012

This is a new, genuine Audi part.