These really can be for all ages, but they’re great for kids, either as flashcards or as playing cards that keep the wild plants in front of them. These are a good tool, but not a stand alone field guide. There is limited information on the back of each card and some of the photos are not great for identifying. So they’re good for fun and learning, but should be used with other books for more information. They are the size of a regular deck of cards.