Made for us by the Baronyx Knife Co. Their "Arctic Fox" Sportsman's Puck has an ANSI 240 grit on the darker, coarse side, 400 grit on the other, arctic white side. The manufacturer recommends a thin film of water be used to keep the pores of the stone clear while sharpening, but you can use it with your honing oil of choice and use a bit of soap to clear out clogs. The coarse side of the stone readily erases scratch marks from a file as well as minor dings in an edge. The “Arctic Fox sapphire ceramic blend” makes up the fine face. The manufacturer states it will “bring the edge to a hazy mirror finish that easily shaves”. We just know it does good service to a blade.