Opel Astra J 1.4 Turbo 2019 Owner's Manual page 40

38 Seats, restraints
Height adjustment
1. Pull belt out slightly.
2. Shift the height adjuster upwards
or press button to disengage and
push the height adjuster
downwards.
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.
Unfasten
To release belt, press red button on
belt buckle.
Seat belts on the rear seats
The seat belt for the rear centre seat
can only be withdrawn from the
retractor if the backrest is engaged in
upright position.