See also:

Treadwear indicators
Narrow bars (tread wear bars) that are distributed over the tire tread. If the tire tread is level with the bars, the wear limit of 1/16 in (1.6 mm) has been reached. ...

Cleaning the rear view camera
– Use clear water and a soft cloth to clean camera lens 1. Do not clean the camera lens and the area around the rear view camera with a power washer. ...

Removing the ball coupling
Observe the manufacturer's installation instructions. Press the protective cap into the ball coupling recess. Make sure that the protective cap is firmly in place. ...