Item Type: Cylinder Piston Assembly OE Number: 1123 020 1209, 1123 030 0408 Material: Die cast aluminum Cylinder Diameter: Approx. 42.5mm/1.67in Fitment: Replacement for Stihl MS250 MS230 1OE Number: The referencing OE number of this cylinder head piston kit are 1123 020 1209, 1123 030 0408, which is molded depend on the original data. 2Fitment: The 42.5mm cylinder piston kit is a replacement for Stihl MS250 MS230, please check the model of your chainsaw before ordering. 3High Performance: The cylinder can work normally under harsh conditions, effectively improve engine displacement, performance, horsepower and torque 4Advantages: Low noise, low expansion coefficient, improved heat dissipation, strong power and low fuel consumption, lower friction surface as well as long service life. 5Material: Made of die cast aluminum material, high strength, not easy to deform, strong impact resistance, which can reduce engine shake and make driving more stable.Please double check the part number of your item, matching information is for reference only. If you are unsure of the item, please contact us before buying to avoid unnecessary return, thanks 1 x Cylinder 1 x Piston 2 x G Ring 1 x Pin 2 x Gasket