Leave it to Chef's Choice to create the ultimate sharpening stones, 100% diamond abrasives permanently bonded to an ultra-flat steel plate. With a grit size ideal for single-stone sharpening, these stones sharpen any type of cutlery steel, from soft carbon steel to hard stainless steel. The stones are affixed to a precisely-constructed, solid-hardwood box, with rubber feet to keep the box from slipping and a cover to protect the stone when not in use.