Wusthof 10" wide diamond sharpening steel, fine (SKU 3039705226). Diamond-coated rod for dull or moderately sharp knives. Fine = 240 grit (European standard); width 19 mm (0.75"). Made in Germany. Wusthof recommends a honing steel for daily or weekly maintenance because this rod removes a little metal. Specs from Wusthof's 10" diamond wide-fine page.