Opel Automobile Owner's Manual page 54

54 Seats, restraints
Loose or bulky clothing prevents the
belt from fitting snugly. Do not place
objects such as handbags or mobile
phones between the belt and your
body.
9 Warning
The belt must not rest against hard
or fragile objects in the pockets of
your clothing.
Height adjustment
1. Pull belt out slightly.
2. Press button.
3. Adjust height and engage.
Adjust the height so that the belt lies
across the shoulder. It must not lie
across the throat or upper arm.
Do not adjust while driving.