Isofix fittings provide a rigid point with which to anchor the car seat The Duo Plus Isofix is fully compatible with the Isofix system in over 130 models of car, with more models continuously being added. Please check here to see if your car is Isofix compatible. Using the Isofix system is quick, easy and minimises the chances of incorrect installation Once installed correctly the chance of a slack installation is removed. Also due to the simple push-click operation the chances of incorrect installation are greatly reduced. The Duo Plus Isofix offers increased protection in the event of a crash where the seat and its occupant immediately take part in the deceleration of the vehicle. A patented 'Pivot' link ensures the Duo Plus Isofix limits the forward movement of your child's head in a crash. Also fits cars without the Isofix system using a standard lap and diagonal seat-belt - ideal if you mainly use a car compatible with the Duo Plus Isofix but sometimes need to travel with your child in an additional car. Isofix car seats are car specific.