Spyderco Tri-Angle SharpmakerThe key to sharpening any cutting tool is removing the steel at the edge while maintaining a consistent angle between the blade and the stone. Spyderco's Tri Angle Sharpmaker takes the mystery out of this process and enables anyone to sharpen a knife effectively with just a few minutes' practice. Its durable ABS plastic base contains keyed holes that accurately set the stones' sharpening angles at a 30 (15 each side) or 40 (20 each side) for