The Yuchparts 4223-190-1001 recoil starter rope pulley is specifically designed to work flawlessly with the Stihl TS420, TS400, and TS410 concrete cut-off saws. This part ensures a smooth transition between the saw's work chamber and the engine, reducing wear and tear on both components. The Yuchparts pulley's compatibility is assured by the matching 4223-190-1000 part number, enhancing the system's precision and reliability. For optimal performance, ensure that the existing recoil starter rope on your Stihl saw is replaced with this Yuchparts pulley, providing a significant upgrade to your saw's efficiency and longevity.