There are a few main differences between European car seats and American car seats, one of the most obvious being the European adoption of the ISOfix.
This was recommended by the United Nations and utilized by the European Nations in the mid-1990s.
The US National Highway Traffic Safety Administration opted not to utilize this system, focusing more solely on the LATCH system because “there is likelihood that the support leg would be misused if the installation requires further action from the parent.”
American car seats are illegal to use in most of the rest of the world due to the addition of the chest clip; the buckle on the seat must be operational by a single button or similar device. It must only lock when all pieces are in it.
The button also has to be red and no other part of the buckle can be in this color. This makes it easier in case of an emergency. This means there are NO CHEST CLIPS.