ATVATP 42.5mm Piston Cylinder Kits for STIHL 023 025 MS230 MS250 Chainsaw Fitment: STIHL 023 025 MS230 MS250 Cylinder Size is 42.5mm Replacement Manufactures Part Number :1123 020 1209, 1123 030 0408 3Month warranty Professional and responsible customer service, shop with confidence!