Sprocket rim, drum & bearing 3/8" fits Stihl 029, 034, 036, 039, MS290, MS360, MS390 Quality aftermarket sprocket rim, drum, bearing. Fits: Stihl 029, 034, 036, 039, MS290, MS360, MS390.3/8" pitch, 7 tooth, small, OD: 3 1/8"