Pro Spur Sprocket / .325" Pitch, 7 TeethPack Size:1Carlton 6-100961X, GB ST305-J7N, Oregon 106657X, Ref No SST305-27N, Stihl 1123 640 2015, Stihl 1123 640 2074NHC 085-6217, Stens 085-621Stihl 017, 018, 018C, 019, 021, 023, 023C, 025, MS170, MS180, MS190, MS210, MS230, MS250, MS250CPitch: .325", Crank Diameter: 10 mm, Drum ID: 2.600 ", Teeth: 7, Bearing included