The STIHL 11151901600 Starter Spring is an authentic OEM replacement component crucial for the recoil starter system in a wide range of STIHL chainsaws, including models 017, 018, 021, 023, 025, MS 170, MS 180, MS 210, MS 230, and MS 250. This precision-engineered spring ensures the starter rope retracts smoothly and maintains proper tension, providing reliable and consistent engine starts. Replacing a worn or broken starter spring with this genuine STIHL part restores the original functionality and extends the lifespan of your equipment's starting mechanism.