Buick 2004 Rainier Owner's Manual page 44

Lower Anchorages and Top Tethers
for Children (LATCH System)
Your vehicle has the LATCH system. You'll find
anchors (A) in the rear outside seat positions.
This system, designed to make installation of child
restraints easier, does not use the vehicle's safety belts.
Instead, it uses vehicle anchors (A,B) and child restraint
attachments to secure the restraints. Some restraints
also use another vehicle anchor to secure a top tether
strap (C).
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