STIHL RAPID™ Super Klassic is an extremely fast-cutting chain. The “Klassic” designation includes special cutter geometry which provides excellent control characteristics and very good chip flow, enhancing overall cutting efficiency. Its cutter and tie strap design reduces vibration levels significantly while still utilizing the aggressive full-chisel design. The razor-edged, square-cornered cutter shape ensures minimum chain friction for an exceptionally smooth and clean cut in hard or frozen wood. It offers excellent cutting and plunge-cutting efficiency. RSK chain typically cuts faster than RM chain, but requires careful sharpening and maintenance to continue to perform well. Applications: Ideal for use in the forestry industry for felling, bucking and limbing on medium to high-powered chainsaws. These aggressive cutting chains are designed for trained professional cutters with extraordinary cutting needs. STIHL recommends using low-kickback, green-labeled chain and green-labeled reduced-kickback bars on all powerheads.