Protect your notebook (choose here) with metal corners and prevent your book cover from damage. By purchasing this upgrade your notebooks will be fitted with four metal corners. There are two sizes - depending on the size of the book you are purchasing will depend on the book corners I use. The smaller corners have a cut our decoration (for most books A5 and smaller) Larger books will have sold metal corners. They are silver metal in colour. This listing is for four book corners.