Manufacturers have quality controls to ensure seats are properly put together and packaged. However, it is not guaranteed that the included instructions are always adhered to and correctly followed. Up to 95% of the safety seats that are installed may not be the right seat for the child, may be hooked into the vehicle loosely, may be hooked with an incompatible belt in the vehicle, may have harnesses incorrectly fastened in some way, or may be incorrectly placed in front of air bags. In 1997, six out of ten children who were killed in vehicle crashes were not correctly restrained.