1Fitment: Our cylinder piston kit is precisely engineered and produced on the base of original standards, perfect replacement for Stihl MS181 MS211 MS181C MS171. 2Oem: The OEMs of our cylinder piston kit are 1139 020 1201 and 1139 030 0401 for reference, please check the part number of your item before purchasing. 3Excellent Performance: Our cylinder piston kit improves heat dissipation, and has strong driving force, but with low noise and fuel consumption during operation, making the engine run more smoothly without burden. 4Longer Service Life: Our cylinder piston kit is made from die cast aluminum, which is not easy to break, anti aging, anti rust and wear resistant, durable enough for supporting a lasting time. 5Direct Replacement: The superior cylinder piston kit is especially designed for Stihl chainsaw with high accuracy and perfect fitness to meet your demands, allowing you to directly replace the old or damaged part.