The group 1 seat is dedicated for children weighing between 9 and 18 kg, i.e. up to about 4 years of age. It is the second child car seat after the carrier to which you can switch when the child's head starts to protrude beyond the contour of the shell, or the child reaches the maximum weight or height declared by the manufacturer. The change is best made when the child can sit up unaided. Seats in this category can be mounted using a car belt or a dedicated or integrated ISOFIX base. Forward-facing (FWF), rearward-facing (RWF) and rotating seats are available on the market. A large proportion of seats in this category have the option of reversing the direction of mounting by turning or removing and re-mounting the seat.