The i-Size, or Regulation R129, is legislation for car seats that uses a new method of testing car seats for infants and children, including a new side-impact test. i-Size seats are chosen based on the child's height to ensure that the child has the correct size for the seat.
i-Size car seats are considered the safest, with improved head and neck protection. And this is because: Child safety seats for special needs are safer than the rest:
The results of side-impact crash tests are evaluated within the i-Size standard.
i-Size safety tests are completed using advanced Q dummies, which have more sensors than the dummies used for R44 testing.