SPROCKET SPROCKET COMPATIBLE WITH MODELS: 017 018 019 021 023 025 MS210 MS230 MS250 MS250C MS181 3/8" (91) 7 TEETH INNER HOOK: 66mm Bore diameter: 13mm Overall height: 27.5mm ORIGINAL RING: ROLLER CAGE: 37325 STIHL CODE: 100962X ORIGINAL CODE: AT