This 400 grit Chosera is hard, cuts quickly, and wears slowly. As the coarsest stone in the Chosera lineup the 400 is used for fast steel removal when repairing damaged edges, thinning knives, and resetting bevels. All Chosera stones are splash and go and the manufacturer recommends a quick soak. Don't perma soak these stones. The stone measures 210mm x 70mm x 20mm.