Fisher Price group 1,2,3 high back booster suitable from 9kgs/20lbs to 36kg/79lbs (9 months to 11 years approx.) Height adjustable head support with side impact protection. Used with integral 5 point harness between 9kg - 15kg/33lbs (9 months to 4 years approx.) then with the adult car seat belt from 15kg to 36kg (4 to 11 years approx.). Harness is tightened using a one pull adjuster strap and loosened by pressing a harness release button and pulling on the harness.