Oldsmobile 2001 Silhouette Owner's Manual page 54

CAUTION:
You can be seriously hurt if your shoulder belt is
too loose. In a crash, you would move forward
too much, which could increase injury. The
shoulder belt should fit against your body.
To unlatch the belt, just push the button on the buckle.
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Rear Safety Belt Comfort Guides for
Children and Small Adults
Your vehicle may have rear shoulder belt comfort
guides. This feature will provide added safety belt
comfort for older children who have outgrown booster
seats and for small adults. When installed on a shoulder
belt, the comfort guide better positions the belt away
from the neck and head.
If your vehicle has a split bench seat in the third
row, there is one guide for each outside passenger
position. To provide added safety belt comfort for
children who have outgrown child restraints and for
smaller adults, the comfort guides may be installed
on the shoulder belts.