If your original VW strut mounting bolts are rusted or broken, correct replacements are hard to find. The commonly available 10mm threaded bolt has too large a head (17mm), so your socket has a hard time fitting in between bolt and strut tube. These twelve point headed bolts are very compact, strong, and are zinc plated for rust prevention. A 10mm twelve point socket is needed for installation. Grade 12.9. Made in USA.