The Britax Römer "Kidfix M" can be fastened with Isofix as well as with the car seat belt.

- Isofix attachment: This is the recommended method where the Isofix arms are hooked into the appropriate points in the car. The indicators should turn green to show correct attachment.
- Car belt attachment: If your car does not have Isofix, the child seat can also be secured using the 3-point car belt. In this case, the seat must be positioned so that the car seat belt runs through the guides provided on the child seat and the seat rests securely on the car seat.

In both cases, however, the child is always secured with the car seat belt. The child seat serves as a high seat and guides the car seat belt into the correct position to ensure the child's safety.