My son, who is 23 months tomorrow, was able to unlatch the buckle on the Graco carsear we bought. However, with this type of chest clip, he is unable to get himself unbuckled and therefore is safe. I like the fact that you can just move the shoulder harness up and down without rethreading it like most carseats. Also, the tightening mechanism on the side is much nicer than those on the front. I definitely give this carseat a thumbs up! We have two of them - one for each car.