With this self-locking nut you secure the center stand, rear fork and shock absorbers, among others (depending on the scooter model). Anyway, all things that need to be and stay tight.

Therefore, use this original self-locking nut, which is calculated for the mentioned applications.

Always use exactly the right screws, bolts and nuts from Piaggio / Vespa ! They have a certain length and thickness for a reason, and even the choice of materials has been considered.