Motorcycle Engine Air Cylinder Block designed to fit specific models with OEM codes 5UP-11311-00-00, 5UP-11311-01-00, 5UP-11311-10-00, 5UP-11311-11-00, 5UP-11311-20-00, and 5UP-11311-21-00.Compatible with YZ250 models from 1999 to 2024, including YZ250G 2016, YZ250 Mon*ter 2022, and YZ250 50TH 2024.The cylinder is a cylindrical metal component that guides the piston in linear within the engine block.It plays a key role in converting thermal energy into mechanical energy through gas expansion in the combustion chamber, while also enabling compression of air during the engine cycle.Constructed from cast iron, the cylinder features an integrated Ni-SiC composite ceramic coating on the inner wall, which helps reduce friction and supports extended operational life.This design contributes to performance under regular use conditions.Item Type: Cylinder Material Type: Cast iron Condition: Quantity: 1 piece Package Includes: As selected during purchase