DUO 3.0 is a reference book that contains 1000 words, ideal for English language learning. I haven't used it since I bought it. It's in good condition because it was kept covered at the bookstore. - Title: DUO 3.0 - Language: Japanese - ISBN: 978-4-7952-0056-0 - Accessories: With bonus - Number of pages: 1000 pages - Size: A5 size Thank you for looking.