ATVATP Oil Worm Spring Gear for STIHL Chainsaw 017 018 MS170 MS180 021 023 025 MS210 MS250 MS230 Fit for STIHL 017 018 MS170 MS180 021 023 025 MS210 MS230 MS250 chainsaw Package include 1pc oil worm gear Made by top quality and durable material, use for a long time 3Month warranty Professional and responsible customer service, shop with confidence!