Oregon PowerNow 548179 14-Inch Replacement Saw Chain With Sharpening Stone (Older Model) Top-sharpening design allows the cutters to be sharpened in seconds on the saw. Pull the PowerSharp lever on the PowerNow chainsaw for 3-5 seconds. Chisel-style cutters deliver efficient cutting and excellent stay-sharp. Ramped depth gauges and ramped guidance drive links deliver smooth cutting action and low-kickback performance. The Oregon PowerNow 548179 Replacement Saw Chain, PowerSharp 14-in (includes sharpening stone) is low-kickback per ANSI B175.1 & CSA Z62.3. The Oregon PowerNow 548179 Replacement Saw Chain includes a sharpening stone that is designed to be used ONLY with the Oregon PowerNow chainsaw.