The Nikasil 49mm Cylinder Kit is the perfect replacement for your Stihl MS391 chainsaw, and it's completely compatible with the OEM 1140-020-1204 piston. This kit includes all the essential parts you need to create a new cylinder, including piston, rings, and clips. Made with durable and high-quality materials, this kit ensures that your chainsaw's performance remains top-notch, even after numerous fuel refills. With its sleek and ergonomic design, this Nikasil Cylinder Kit is an excellent choice for those looking for a reliable and efficient chainsaw fuel system replacement. Invest in this kit today and enjoy superior performance and efficiency.