Don't judge this book by its cover! The Hidden Real Book Lock Box by Barska is designed to provide a safe, reliable and low-profile hiding place for your most valuable possessions, documents, jewelry, or cash. While the inner walls are made of steel, on the outside it appears as a real book entitled The New English Dictionary. It naturally blends in with the rest of your library on your bookshelf, making it virtually impossible to detect, and creating a safe hiding place for your valuables..