These diamond sharpeners consist of a handle and a diamond pad, designed to keep the blade stationary and move the diamond over in a sweeping motion. No lubrication necessary. Available in different grades from fine to coarse, these can be used for touchup (start with fine and move to extra-fine) or reworking a damaged blade (start with Coarse and move to Medium). Well worth having a Medium and Fine in the tool-kit for all kinds of blades from grafting knives to secaterus. These can be rejuvinated by scrubbing with some ajax, warm water and an old toothbrush.