Description: 19, silver. The lock pattern is located against the middle on the lockable bolts and is therefore difficult to reach with a screwdriver, for example. The top of the lockable bolt rotates and is therefore very difficult to loosen without the right wrench. A solid connection between wrench and bolt facilitates installation and removal, and generally eliminates the risk of crooked tightening. Lockable wheel bolts specially developed for Volvo Cars, which improves safety.