The forces of an impact are distributed over the protective body and reduced by its energy-absorbing materials. This system resembles an inflated airbag and significantly helps to reduce forces in the event of an accident. The belt does not cut in, protecting the sensitive neck and shoulder area as well as the internal organs. The one-handed adjustable protective body perfectly adapts to the child's body for maximum comfort and also offers significantly more upper body freedom of movement, providing a high level of safety in the event of a frontal impact compared to conventional harness systems. The patented adjustable headrest shifts the center of gravity of the head backward, preventing the dangerous forward tilting of the head while sleeping. This ensures that in the event of a side impact, the sensitive head and neck area is protected, as the head remains within the safety zone of the seat. The L.S.P. system of the Pallas S-Fix offers increased safety in the event of a side impact. Compared to the L.S.P. system folded in, the forces of a side collision are reduced by about 25% when the L.S.P. is extended in conjunction with the energy-absorbing shell. The one-handed adjustable sitting and reclining position allows parents to set the seat to the sleeping position with just one hand (Group 1). In Group 1, it protects with a height-adjustable protective body that provides airbag-like protection in a frontal impact without constricting. The seat can be easily transformed into a Group 2/3 seat from the Solution family for children from about 3 years old with just a few adjustments.