Ruko 400 Grit Diamond Sharpening Rod Pen Knife Sharpener(4-Inch) Diamond Grit Sharpening Pen, 4-Inch Retractable Rod, Pocket Clip 400 Grit Diamond Dust quickly sharpens Knives, Tools and Fish Hooks Multiple surfaces in One Rod, Concave, Flat and Grooved Channel for Fish Hooks Weight: 2.40 oz Lifetime Warranty