Only Infant Seat Infants should ride rear-facing until they are 1 year of age and 20 pounds. Riding rear-facing helps to protect the head, neck and back of the infant. This seat should be reclined at a 45 degree angle and the harness straps should be at or below the infants shoulders. This seat may be installed with a combination lap and shoulder belt or a lap belt only. This seat is used for infants from birth to 20-22 pounds in weight and until the infant's head is within an inch of the top of the shell.
Some models have a detachable base and can be used with or without the base.
Rear-facing, this seat should be at a 45 degree angle and the harness straps should be at or below the infant's shoulders. This seat may be secured into the vehicle with a combination lap and shoulder belt or a lap belt only. An integrated seat is one that is built into the vehicle seat by the manufacturer. These seats can be used by children over 1 year of age and over 20 pounds. Most integrated seats are able to be used by children up to 40 pounds with harnesses.