My kid has been slowly collecting pokemon cards and has requested a binder to put them all in. There are so many designs to choose from. He picked this one simply because he liked the design. The binder is nice and sturdy. It even came with the sleeves to put the cards in. The binder gets heavy even before it is filled with 900 cards. The sleeves sometimes get caught on the binder rings as we flip the pages. Even though it fits 900 cards, I would say it would work best with 500-600 cards. This will make it easier to flip the sleeves without being caught on the binder rings. Kids love to flip and look at the cards all the time, so with 900 cards filled, it would be a bit tough. Otherwise, this binder is a great buy!