GMC 2003 Yukon Denali User Manual page 47

Third Row
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Lap Belt
When you sit in the center seating position in the third
row, you have a lap safety belt, which has no retractor.
To make the belt longer, tilt the latch plate and pull it
along the belt.
To make the belt shorter, pull its free end as shown
until the belt is snug. Buckle, position and release it the
same way as the lap part of a lap-shoulder belt. If
the belt isn't long enough, see Safety Belt Extender on
page 1-47.
Make sure the release button on the buckle is positioned
so you would be able to unbuckle the safety belt
quickly if you ever had to.
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