The Kershaw Honing Steel is sometimes mistakenly sharping steel; the Kershaw steel isn't about sharpening, but about honing. Eventually over time the sharp edge of a Kershaw blade with naturally bend and warp after a certain amount of use. Invisible to the naked eye, the micro-bending that happens will affect the blade's cutting performance. The Honing Steel gently realigns the edge, straightening it and returning your knife to its best performance.
To use the Kershaw Honing Steel, draw the entire length of one side of the edge of the blade across the steel several times. Then draw the other side of the blade across the steel an equal number of times. Doing this once a week will extend the time between sharpenings — and make food preparation a more pleasurable experience. Information from Kershaw.