GMC 1998 Savana Van Owner's Manual page 55

A rear-facing infant restraint (B) positions an infant
to face the rear of the vehicle. Rear-facing infant
restraints are designed for infants of up to about
20 lbs. (9 kg) and about one year of age. This type
of restraint faces the rear so that the infant's head,
neck and body can have the support they need in a
crash. Some infant seats come in two parts
--
the
base stays secured in the vehicle and the seat part
is removable.
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