We bought these seats for our twin 3 year during a one-month trip abroad. We had taken in hand luggage, we could store toys, books, and some cookies and candy. By car, very convenient for short trips, not comfortable for long journeys to do with children + great because when the small fall asleep, nothing holds their heads. A little heavy to be worn as a backpack by a child (even empty, with the inner shell, this makes weight). Solid and attractive design