Savior 38mm Big Bore Cylinder Head Piston Rebuild Kit Ring Pin Clips Assembly for STIHL FS120 FS200 FS250 BT120 BT121 Trimmer Replace 4134 020 1212 High quality repair cylinder piston kit Cyliner diameter: 38mm Refer to Part No.: 4134 020 1212 /41340201212 Fit STIHL FS120 FS200 FS250 trimmer