英語と日本語の併記本です。日本語でも読めます。This book describes the history of the famous “Speed Timer” vintage watch from the world-famous watchmaker Seiko Watch, starting with the first model. The Speed Timer was the world's first automatic chronograph watch with a very large number of products, and there are many models with high historical value among Seiko's sports watches. If you want to know the history and value of your Speed Timer, this book is full of information you need to know. The historical products are described in detail by period, and the book also includes valuable images and documents. The book is full of useful information for watch collectors and antique watch dealers. The text is written in both English and Japanese.