Cadillac GMC Yukon Denali 2005 Owner's Manual page 13

Head Restraints
Adjust your head restraint so that the top of the restraint
is closest to the top of your head. This position
reduces the chance of a neck injury in a crash.
The head restraints tilt forward and rearward also.
To adjust the tilt for either of the front head restraints,
pull it toward you until you hear a click. There are
four positions available: initial position, first click,
second click and third click. Each position will click into
place. After the third position (three clicks) is reached,
pulling the head restraint farther will release it back
to the upright position.
Pull firmly on the top of the head restraint to position it
to your liking.
The rear seat head restraints in your vehicle are
adjustable up and down. Move the head restraint so
that the top of the restraint is closest to the top of your
head. This position reduces the chance of a neck
injury in a crash.
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