The STIHL 96409511972 is a genuine OEM shaft seal, precisely engineered with dimensions of 18 mm inner diameter, 29.6 mm outer diameter, and a stepped thickness of 5/3 mm. This critical component ensures optimal sealing for crankshafts and other rotating shafts, preventing oil leaks and maintaining engine performance. It is a direct replacement part for a wide range of STIHL equipment, including popular chainsaw models like MS 170, MS 180, and MS 251, as well as various trimmers, blowers, and cut-off saws. Manufactured to STIHL's rigorous quality standards, this seal ring guarantees reliable operation and a perfect fit for specified models.