Opel ASTRA Owner's Manual page 48

46 Seats, restraints
Tilt front of switch upwards/
downwards.
Backrest inclination
Tilt switch forwards/backwards.
Lumbar support
Adjust lumbar support using the
four-way switch to suit personal
requirements.
Moving support up and down: push
switch up or down.
Increasing and decreasing support:
push switch forwards or backwards.
Adjustable thigh support
Pull the lever and slide the thigh
support.