Hummer 2004 H2 - Manual (Page 38)

3. To make the lap part tight, pull down on the buckle
end of the belt as you pull up on the shoulder part.
The lap part of the belt should be worn low and snug
on the hips, just touching the thighs. In a crash, this
applies force to the strong pelvic bones. And you
would be less likely to slide under the lap belt. If you
slid under it, the belt would apply force at your
abdomen. This could cause serious or even fatal
injuries. The shoulder belt should go over the
shoulder and across the chest. These parts of the
body are best able to take belt restraining forces.
The safety belt locks if there is a sudden stop or a
crash. The safety belt also locks if you pull the belt
very quickly out of the retractor.
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