RUKO RUK0045-CS 325 Grit Diamond Sharpening Stone is convenienet and easy to use. Diamond Grit Pocket Sharpening Stone with Fish Hook Groove, 3" x 1"; 325 Grit Diamond Dust quickly sharpens Knives, Tools and Fish Hooks; Supplied with Nylon Sheath; Weight: 4.18 oz; Lifetime Warranty