This Tojiro sharpening stone F-431 is a Japanese sharpening stone with a grit size of 1000. Use this stone to sharpen all your Tojiro knives (or other knives, of course). The grain size of 1000 grit is excellent at making and keeping your knife sharp. Is your knife very blunt? If so, we recommend using a coarse sharpening stone first. The stone comes with a practical base, enhanced with non-slip feet. This keeps the stone lying nice and still and also raises it slightly, giving your hands more room while sharpening. The stone is attached to this holder.