This Smith’s JIFF style knife sharpener features a specially designed “V” shaped sharpening slot with two crossed tungsten carbide blades. The carbide blades are pre-set for the correct sharpening angle every time. It is safe and easy to use, and it puts a sharp edge on your fillet or pocket knife with just three or four quick strokes. The JIFF-FISH comes with a built-in scale, tape measure, hook hone, and writing pen. It has a soft grip rubber handle for comfort and safety during use. Use it to sharpen all of your knives and hooks and to weigh and measure your game and fish. Sharpening Instructions: Always keep your fingers inside the hand guard and your thumb securely on the thumb rest indention on the top of the sharpener; otherwise possible injury may occur.