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Here are the different anchorages and fasteners you will find in child restraint systems

Here are the different anchorages and fasteners you will find in child restraint systems


The Child Restraint Systems currently available on the market have different solutions with regard to anchorages and fasteners. We will differentiate between anchorages, and fasteners because they are different elements but equally important for the safe installation of the CRS.

It is important to remember that all children should be seated in a CRS corresponding to his or her physical characteristics, and that those under 18 whose height is equal to or less than 135 cm are obliged to travel in the rear seats. In the article entitled "Child seat legislation in Spain" you'll find all the information you need.


The traditional classification of Child Restraint Systems is divided into four main groups, from Group 0, through Groups 1 and 2, to Group 3, or booster cushions. As you know, Group 0 CRSs also include those of Group 0+, which are seats designed to face in the opposite direction to that of the vehicle, with five-point harnesses to hold the baby. Group 0 are known as baskets and generally offer less protection than those of Group 0+, except in the case of babies with special requirements.

When considering CRS anchorages, we will find two possibilities: using the safety belt to fasten the child seat, or using the ISOFIX system. A harmonized child seat is perfectly safe if it is fastened correctly by using the safety belt, but this system has the disadvantage of it being very easy to make a mistake when installing the CRS: we may forget one of the openings or use the fasteners incorrectly.

With the ISOFIX anchoring system, these mistakes cannot be made, and so for this reason it can be considered a safer system. The ISOFIX system has three anchorage points to the vehicle: two steel supports mounted on the car's chassis which appear through slots in the seat, and a third element which may be one of two types: upper or lower.

The upper type is called Top Tether, and consists of a hook with a cable that passes over the back of the car seat, under the headrest, and down over the back part of the seat, inside the trunk, where it is fastened onto a hook.

Top Tether 

The lower type consists of a foot prop coming from underneath the seat and is adjusted so that it is perfectly anchored to the floor of the car.

As for the fastenings for the different CRSs there are two types: five-point harnesses for the protection of infants in groups 0+ and 1; the safety belt for protecting children in Groups 2 and 3.

Take a look at our info graphic"Always check that the child seat is correctly installed" and "Ways of strapping the child into a child seat".


As you can read in the article"i-Size is the new standard for child car seats, and here's what's new" on the "Drive Safely" website and in our article"The advantages of i-Size child seats", until 2018 two harmonized Child Restraint Systems will have to coexist: traditional and i-Size regulations. The objective of this new harmonization is to reduce the chances of incorrectly installing the child seat to a minimum, because these seats will be compatible with the ISOFIX system and it will not be possible to them using the safety belt. So this will drastically reduce the chances of installing the CRS incorrectly.

Furthermore, the new CRSs will undergo additional side impact tests and it will be mandatory for children up to the age of 15 months to travel facing backward in order to increase their safety in case of collision. The choice of seat will be based on age and height and not on weight, and the seat's fasteners will be safer.


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