This 6-piece piston ring set is designed for N52B30 3.0L naturally aspirated inline-6 engines (2996cc) used in E87, E90, E92, E60, and E61 platforms equipped with 130i and 330i configurations.The set features a 9.3:1 compression ratio and includes pistons, rings, and connecting rods to support a complete engine overhaul.Constructed with cast aluminum pistons and steel rings, it is engineered to maintain efficient combustion and consistent performance.The components adhere to standard dimensional tolerances (STD 0.00) to proper fitment without requiring cylinder boring.This assembly is intended for restoration or maintenance of engine functionality in compatible vehicles.