The Stihl Piston Cylinder Diameter 40 mm (code 1139-020-1202) is an original spare part for Stihl MS 211 chainsaws. Includes piston Diameter 40 mm, compression ring Diameter 40x1.2 mm, piston pin 10x6.5x25, circlip 10, screw for plastic IS-D5.3x41. MN