In the Sirona S i-Size, children can be safely transported backwards from birth up to a size of 105 cm (up to 18 kg, about four years). Optionally, the seat can be used facing forward (from a minimum of 76 cm and 16 months up to a size of 105 cm). With the introduction of SensorSafe, CYBEX combines smart technology with smart design, ensuring that the safety and health of the child always comes first. The system is available for selected Platinum and Gold i-Size child seats. The clip is attached to the belt system and sounds an alarm to avoid critical situations - for example, if the child opens the clip, if it gets too hot or too cold in the car interior, if the child is left alone in the car, or stays in the seat for too long. All alerts are sent via Bluetooth to the connected smartphone and received via a user-friendly app.

Directional Driving Control (DDC) prevents premature use of the forward seating position. This ensures that the forward position cannot be used until the child is at least 16 months old and 76 cm tall. The energy reduction technology of the Sirona S i-Size offers increased safety in the forward position in the event of a frontal impact. It reduces the forces acting on the child's neck in the event of a frontal impact by more than 20% compared to other belt systems. The integrated L.S.P. system of the Sirona S i-Size offers increased safety in the event of a side impact. The forces of a lateral collision are reduced by approximately 25% in conjunction with the energy-absorbing shell.

The Sirona S i-Size is secured by the car's ISOFIX system and does not require buckling up with the car seat belt in both the reverse and forward positions. The colored indicators of the ISOFIX system minimize the risk of operating errors during installation.