Block knife sharpeners are used buy professional Chef’s, Hunters, Fisher men,and every day people that need a Great industrial strength american made knife sharpener. Block sharpeners original sharpeners where made for Production line sharpening. used in slaughterhouses and food processing plants in the 70 and 80. Aka Slaughter house sharpener. Block sharpeners are now made for the public. with there new patent anti slip grip and thumb guide added to sharpeners handle makes it safer for people of all ages and professions to use.