The product is a hardcover book titled "The Mathematical Theory of Black Holes" by Subrahmanyan Chandrasekhar, published in 1983 by Oxford University Press in New York. This book falls under the subject area of Science & Medicine, specifically focusing on Physics. It is a rare collectible item that delves into the mathematical theory of black holes, making it a valuable addition to any science enthusiast's library. The book is a significant work by the renowned author S. Chandrasekhar, offering a deep exploration of this fascinating topic in the field of physics.