Convertible seats can be used rear-facing for infants up 35 lbs and until 1 yr of age and foward facing for children over 1 yr of age and over 20 lbs and less than 42-60 inches tall. A 5 point harness system is the safest restraint for all children under the age of 8. It is always the best practice to continue using your 5 point harness seat until your child has outgrown the seat in either weight or height. Please refer to each individual seat for individual weight and height restrictions.
The American Academy of Pediatrics(AAP) and National Highway Traffic Safety Administation(NHTSA) recommends that children should remain rear-facing until a minimum of 1 yr of age and a minimum of 20lbs.
Britax
Recaro