These standard 84.0mm piston rings are designed for the N55B30 3.0L turbocharged inline-6 engine used in model years 2008–2018.Compatible with 135i, 235i, 335i, 435i, 530i, 535i, 640i, 740i, X1, X3, X4, X5, and X6 vehicles, this set of six piston rings supports proper engine sealing and compression restoration.Manufactured to meet dimensional and material standards, they are intended for engine rebuilds or maintenance to help reduce oil consumption and maintain consistent engine performance.Reference OEM part numbers include 11257594453, 7594453, 11257610297, 7610297, 11257589824, and 7589824 for fitment verification.