Head gasket set compatible with 323xi Z4 X3 models equipped with N52B25, N52KB25 engines, part numbers 512.270, 11127548921, 11127526040, 11137548031, 11117587168.Designed for complete cylinder head replacement, this kit includes all necessary sealing components for engine reassembly.Contains multi-layer steel head gasket, valve cover gasket set, valve stem seal set, exhaust manifold gasket, intake manifold gasket set, lower gasket set with oil pan gasket, and additional small gaskets, seals, and O-rings.Constructed using materials equivalent to or meeting specifications to proper sealing and engine performance.Packaged in an organized container for easy identification and installation.Suitable for use during major engine service requiring cylinder head removal and replacement.