Sharp hooks are critical for angling success, and regardless of what you are told, all hooks will need sharpening from time to time. Our two-sided hook files feature dual sharpening grooves for honing hook bottom and point as well as flat areas for side sharpening of points. Constructed of stainless steel with dual diamond grit surfaces. 4-Inch model has a fine side - 600 grit, and a medium side - 300 grit. 6-Inch model has a medium side - 300 grit, and heavy side - 150 grit.