3" by 1/2" Archone Japanese Waterstone.
The Archone is a simple Japanese waterstone cut in an arch for creating ridelines in shears that would be impossible to hone using a traditional waterstone. While it is not as perfect as a waterstone it gives the closest approximation to a flat rideline without ramping or relaxing the edge. It is quick to use in fast paced situations like hair and pet shows where there is not time to take the shears apart.
The key is two pieces of electrical tape wrapped around the center. One is double thickness. This keeps the stone from riding perfectly flat on the inside of the blade. Because of the twist created along the edge due to the hollow ground the edge at the tip is twisted in slightly more than the back section. The archone allows you to turn the stone around to where the tape is double thick to be able to approximate the correct rideline near the tip. The video should explain this, but contact us if you have questions.