ISOFIX is a standardised fixing fitted now in most modern vehicles. This enables us to use a child seat, a Group 0 base or Group 1 seat, fixed entirely by the ISOFIX points. There will be two anchor points at the base of the seat and for the Group 1 seats sometimes there is a third tether point in the back of the seat. To fit an ISOFIX product, locate the ISOFIX points, click the seat on, push it in securely. By using one of these, it gets round the compatibility issues like buckle crunch and bad anchor points because it is not using the adult seat belt at all.