Fitment and Product Information. Head Stud Kit For Volkswagen/Audi 2.0L (FSI) 4-Cylinder. Cylinder Head Stud Kit – Pro-Series – Cylinder Head – 12 Point Nuts – Chromoly – Black Oxide – Undercut – Volkswagen 4-Cylinder – Kit. WARNING : This product can expose you to chemicals including Styrene, which is known to the State of California to cause cancer.