8 pieces engine pistons and rings set, standard specification, for vehicles equipped with N62B48 4.8L V8 naturally aspirated engine.Compatible with 550i (2005–2010, E60/E61), 650i (2005–2010, E63/E64), 750i/750Li (2004–2009, E65/E66), and X5 4.8i/4.8is (2004–2010, E53/E70).Piston diameter: 93.00 mm Wrist pin diameter: 21 mm Wrist pin length: 54 mm Ring thickness: first ring 1.2 mm, second ring 1.5 mm, third ring 2.4 mm OEM part numbers supported: 11257542292, 11257831889, 11257544952, 11257537124, 11257549510, 11257549511, 11257543324.Standard specification means no cylinder bore expansion required; designed to fit cylinder bore dimensions.Disclaimer: This is a compatible replacement part.Any brand or model mentioned is for compatibility demonstration, not endorsement.