Compatibility: Fits popular chainsaw models including MS250, MS210, MS230 and MS230C for a straightforward replacement. Key specifications: Designed with piston pin ring sizes of 42.5 mm and 40 mm to match factory dimensions and ensure correct clearances. Purpose and benefits: Ideal for engine rebuilds and routine maintenance — restores cutting performance, reduces oil and compression loss from worn parts, and extends the useful life of the chainsaw. Durable construction: Manufactured from materials chosen to withstand heavy use and demanding operating conditions, helping the engine tolerate heat, vibration, and wear. Easy installation: Simple replacement process allows users to install parts without professional assistance, saving time and repair costs. Performance advantage: Precise fit delivers smooth operation and improved engine efficiency by maintaining proper compression and minimizing friction. Use scenarios: 1) Routine service: Replace worn piston pin rings during scheduled maintenance to restore compression and cutting power on MS250, MS210, MS230 or MS230C machines. 2) Engine rebuild: Use as part of a motor rebuild kit to bring a tired chainsaw back to reliable working condition for professional or home use. 3) Job-site repair: Perform a quick field replacement to get a chainsaw back into service with minimal downtime when working on property maintenance, forestry tasks, or construction clean-up. What you get: Correct-size piston pin ring components (42.5 mm and 40 mm) compatible with MS250, MS210, MS230 and MS230C, built for durability and straightforward installation to restore and maintain chainsaw performance.