The Oregon Power Sharp bar is an easy to use, precision sharpening system that allows chainsaw users to sharpen blunted chains in a matter of seconds. Simple to fit & easy to use, the Power Sharp bar attachments sharpens chains in 3 to 5 seconds (up to 10 on electric models) & it does so while the chain is still mounted on the saw, meaning it doesnt need to be removed which in turn means that you can focus more time & effort of cutting, rather than sharpening. * Please note: The sharpening stone is not included with this kit. A sharpening stone is supplied with the Oregon Power Sharp chains.