With this electric side-edge sharpening tool, you can easily put a razor-sharp edge on a pair of skis or a snowboard. The circular diamond disc is adjustable in one-degree increments from 90 degrees to 85 degrees and backed by a steel spring, which ensures constant pressure regardless of stone wear. Includes fine diamond stone (installed); additional coarse and medium discs are available. Plugs directly into the wall; no batteries needed. 110-240 volt.