The product is a set of 15 hardcover books from the 1979 Book of Knowledge series, along with the 1980 Book of Knowledge Annual. These books, authored by E.V. McLoughlin and published by The Grolier Inc., are filled with encyclopedic information in English. The set is a valuable reference resource for those interested in a wide range of topics, making it a sought-after collectible for book enthusiasts and scholars alike.