Oregon 560510 PowerSharp Replacement Saw Chain Kit for CS300 with Onboard PowerSharp System, 16" 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 holds excellent cutting edge 2-3 times longer Ramped depth gauges and ramped guidance drive links deliver smooth cutting action and low-kickback performance The Oregon PowerNow 560510 Replacement Saw Chain; PowerSharp 16-in (includes sharpening stone) is low-kickback per ANSI B175.1 & CSA Z62.3