Material: Aluminum Design and Style: Standard 0.00 specification, not intended for cylinder expansion Cylinder Bore: 84.00mm Ring Thickness: 1st ring 1.2mm, 2nd ring 1.5mm, 3rd ring 2.0mm Compatibility: N55B30 and N55B30A 3.0L L6 (2979cc) Twinpower Turbo engines OEM Numbers: 11258619196, 11257610297, 11257610298, 11257589824, 11257587914 This 6-piece piston ring set is designed for use with specific inline-6 twin-turbo engines.Constructed from aluminum, the components are engineered for under demanding operating conditions.The standard 0.00 size allows installation without cylinder block modification, supporting consistent engine . The set is compatible with models including F20, F21, F30, F10, X3, X4, X5, X6, E82, and E88 equipped with the N55B30 or N55B30A engine.Each ring set includes three rings with incremental thicknesses of 1.2mm, 1.5mm, and 2.0mm to effective sealing and reduced oil consumption.Designed for a fit in 84.00mm cylinder bores, the rings support and improved engine efficiency. Engineered to meet OEM specifications, the set supports compliance with emission standards.The material withstands operating temperatures up to 105°C, stable during extended use. This product is an aftermarket solution.Brand names are mentioned only to clarify compatibility with specific models.