The DMT Diafold Diamond File is a 4-inch tool designed for knife sharpening. Manufactured by DMT in the United States, this double-sided file is perfect for keeping your knives in top condition. With XX Fine and X Fine grits on opposite sides, this file ensures a precise and sharp edge every time. Ideal for professionals and enthusiasts alike, this high-quality product from DMT is a must-have for anyone looking to maintain their kitchen knives.