35mm Piston Rings Kit For STIHL FS120 FS120R FS300 BT120C BT121 BT121Z #4134 030 2011 Trimmer Strimmer Brush Cutter 35mm Piston Rings Kit For STIHL FS120 FS120R FS300 BT120C BT121 BT121Z #4134 030 2011 Trimmer Strimmer Brush Cutter. Sale price : $7.40 Category : Tools