The Manual Sharpener that Really Works! The M440 ensures razor-sharp edges, sharpening after sharpening It combines 2-Stage sharpening, precision sharpening angle control and 100% diamond abrasives in an easy-to-use design that is safe for quality knives. The M440 puts a long–lasting double-bevel edge on a broad range of knives, including fine edge (straight edge) kitchen, fishing, hunting and pocket knives. Perfect for the kitchen, tackle box, toolbox or glove compartment. Dishwasher safe. Easy to use right- or left-handed. Made in the U.S.A.