GMC YUKON XL 2003 Manual page 44

Lap Belt
When you sit in a center seating position other than in
the second row you have a lap belt.
A lap safety belt does not have a 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 1-43.
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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