Hummer 2007 H3 Owner's Manual page 399

5. Turn the wheel wrench clockwise to raise the
jack head to the lifting point.
CAUTION:
{
Getting under a vehicle when it is jacked
up is dangerous. If the vehicle slips off
the jack you could be badly injured or
killed. Never get under a vehicle when it
is supported only by a jack.
CAUTION:
{
Raising your vehicle with the jack
improperly positioned can damage the
vehicle and even make the vehicle fall.
To help avoid personal injury and vehicle
damage, be sure to fit the jack lift head
into the proper location before raising
the vehicle.
399