Car seats that are suitable from 6 months of age are great to use as a follow on car seat after having used a capsule for your newborn baby. These convertible booster seats or forward facing seats cannot be used from birth as they are not rearward facing car seats which is a specification within the Australian standards requirements for newborns. With convertible booster seats, once your child's shoulder level reaches the upper height marker on the seat, which is approximately 4 years of age, the seat changes from using its own internal harness to using the actual belt of the car itself to secure the child. This effectively turns the seat into a booster seat. The forward facing car seat category however allows the use of the internal harness right up to eight years old, keeping your child safer for longer as internal harnesses are considered safer than using the vehicles own belt.