Child Booster Seats are designed for children from 14kgs to 26kgs.

Child booster seast are generally made from foam and are designed to
raise the child in the car. Although they are suitable from 14kgs it is
important to consider that the booster sits in your car it is not anchored in.
You also use the cars seat belt even with a harness - you need to consider
whether the child will undo the seat belt at anytime. Ideally a child should
be around 4years of age, if not maybe consider the Convertible boosters as
another option.