6Pcs Pistons and Rings Set STD 22mm with 84.5mm cylinder bore and 54mm wrist pin length, designed for N55B30 and N55B30A engines.This set includes 6 pieces of pistons and rings with ring thickness of 1.2mm for the first ring, 1.5mm for the second ring, and 2.0mm for the third ring.Constructed from grade aluminum, the pistons are engineered for and consistent performance under conditions.The set is compatible with various vehicle models including those with F10, F20, F30, F80, M135i, M235i, X3, X5, and X6 chassis codes.Featuring OE specification design with reference number 11258619196, this piston and ring set allows for direct replacement and simplified installation.Engineered to meet fitment standards, it supports engine and performance restoration.