Spyderco’s Golden Stone sharpening device is all curves and angles for sharpening any edge. U.S. made, from Alumina Ceramic it’s created though a process combining a bonding agent with alumina particles (that are actually synthetic sapphires 15 to 25 microns in size). Its then kiln fired at temperatures exceeding 3000 degrees F (1649°C) where it reaches 9 (out of 10) on a Mohs hardness scale and is cooled in stages. Ceramic sharpeners are used dry without oil or water. The fine grit Golden Stone is closed-cell and won’t wear with usage or time, excelling at polishing and professionally finishing any edge. The angles and sides include: a flat stone, a groove for de-burring and honing pointed objects. Holding the stone vertically on a tabletop and tilting it from one side to the other raises one edge off the tabletop, creating a 20° angle (40° total angle) for sharpening knife blades. Both sides are elliptical. One side has a large radius for sharpening PlainEdges, the other, a smaller radius for SpyderEdges (serrations). Positioned on its’ side horizontally creates a 12.5° angle for sharpening scissors. Suede leather carry case doubles as a non-skid counter top pad for tabletop sharpening. To clean: rinse in water and dry. It is temperature resistant, dishwasher and autoclave safe. Currently does not come with any instructions, packaging or dvd support.