The product is a 3-volume box set of "Kristin Lavransdatter" trilogy by Sigrid Undset, published by Alfred Knopf in 1946. The books are in English and the author is Sigrid Undset. The box set includes all three volumes of the trilogy, making it a comprehensive collection for readers interested in Undset's work. It offers a complete reading experience of the novels in a convenient format, with the publisher's stamp adding to the value of the set.