RACEORLY Piston Ring Set STD For 550i 750i X5M X6M F10 E70 4.4L V8 N63 S63 STD specification (no cylinder bore expansion required) Cylinder bore diameter: 89 mm Piston pin diameter: 22 mm Ring thickness: 1.5 mm / 1.5 mm / 2.0 mm Split design piston ring set Compatible with N63B44A and S63B44A 4.4L V8 twin-turbo engines (4395 cc) Fits 550i Gran Turismo (2010–2017, F07), 550i / 550ix (2010–2017, F10/F11), 650i / 650ix (2011–2017, F06/F12/F13), 750i / 750Li (2008–2015, F01/F02/F03/F04), X5 50i xDrive (2009–2018, E70/F15), X6 50i xDrive (2007–2018, E71/F16), X5M (2010–2013, S63B44A), X6M (2009–2014, S63B44A) Includes one set of piston rings for 8 cylinders OE number reference: 11257574822