From the Manufacturer:
The Neptune Car Seat is suitable for Groups 1/2/3, suitable for children from 9-36kg (approx one -12 years in age).
When the seat is used in Group 1 the child must be fastened in using the car safety harness. The 5-point harness has comfortable shoulder pads and an easy to use one-pull harness adjustment. The 5 point harness can be removed and replaced by the standard car safety belts for use in Group 2 and 3.
The ergonomic adjuster makes it easy to regulate both the height of the safety belts and the headrest at the same time; this will ensure your child travels safety and comfortable as it grows. It is fitted with special side protection for your child's head and shoulder, for extra safety in case of impact; the reinforced padding in the lumbar zone and the seat guarantees extra comfort.