A quality non genuine clutch sprocket bearing for the Stihl 017, 018, 021, 023, 024, 025, 026, 029, 034, 036, 039, MS170, MS171, MS180, MS181, MS210, MS211, MS230, MS231, MS250, MS251, MS240, MS241, MS260, MS261, MS270, MS271, MS290, MS291, MS310, MS311, MS390 & MS391.