The Torsion Spring 4128 182 4505 is a high-quality replacement part designed specifically for the STIHL FS55R , manufactured by Farmertec in China. This torsion spring plays a critical role in maintaining the tension and performance of the mower deck, ensuring optimal cutting efficiency and consistency. With its durable construction and precise engineering, this torsion spring is a vital component for keeping your lawn mower operating at its best.