The product is a 25-book set of Mo Willems' "An Elephant and Piggie" chapter books for kids. Each book in the series is in paperback format and written in English. The books center around the theme of friendship and are part of the "An Elephant and Piggie Book Ser." published by Hyperion Books for Children in the United States. Perfect for children who enjoy engaging and entertaining stories, these books are sure to become a favorite for readers young and old.