My little one seems to always be fascinated with buckles/straps, whether it's on the grocery cart, stroller or car seat. She will literally play with buckles on her stroller over any other toys in the room.  All of the Buckle Toys would have suited this need, but we got the Backpack because her big brother just started Kindergarten and she is always asking to put his backpack on and walk around the house.  Of course, it's as big as she is, so this has been perfect! She gets to play with the buckles whenever the mood strikes and wear a backpack more her size.  Plus the buckles are really helping her to learn her colors.  A great purchase!