Hummer H2 2010 Owner's Manual page 171

A. Bottom of the spare tire.
B. View displayed by the camera.
C. Corner of the rear bumper.
Notice: The spare tire extends farther away from
rear of the vehicle than the trailer hitch shown on
rear vision camera display. The spare tire could hit
an object even though there appears to be enough
distance on the display between the trailer hitch and
objects behind you causing vehicle or property
damage. Do not use this system to judge the
distance between the spare tire and objects
behind you.
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