We do not recommend using booster seats without a backrest for your child. When compared to seats with a backrest, booster seats pose a higher risk of injury. The main problem is the missing side protection. A booster seat with a backrest has side protectors that prevent the child from hitting the window in the case of a side impact collision. With a booster seat, however, the vulnerable parts of the child’s body are not sufficiently protected. Additionally, the routing of the seat belt cannot be adjusted to the height of the child so that the belt is often too close to the neck. Due to the compact design of a car seat with a backrest, the child not only sits much firmer in the seat itself but is also much better protected due to the correct position of the seat belt. For children that have reached a weight of 15 kilograms or a height of 100 cm (approximately four years old), CYBEX has the Solution series of high back booster seats. These allow growing kids to sit comfortably in the car, while including safety features such as Linear Side-impact Protection and a reclining headrest to help prevent your child’s head from falling forwards and becoming vulnerable in the event of a crash. In order to assure the safety of your child, we highly recommend using our Solution series.