The D-Sharp pocket knife sharpener features four sharpening angles (17, 20, 25 and 30 degrees) in 600 grit diamond. It also has a fine 800 grit ceramic benchstone that can be used for polishing straight or serrated blades. Compatible with all Lansky Controlled-Angle Systems & Turn Boxes. Perfect as a Lansky System accessory, or as a stand-alone sharpening solution.