Nylon screw and black nut.
Color Code:
- Yellow: Screw cap for the yellow number plate at the back of the car
 - White: Screw cap for the white number plate at the front of the car
 - Black: Screw cap for the black lettering on the number plate
 - Blue: Screw cap for the for the left side of the number plate where the flag of EU or UK may be shown