Piston Ring Set for BMW 550i, 750i, X5M, X6M (F10 E70 4.4L V8 N63 S63) Upgrade your engine's performance with this premium Piston Ring Set, designed to fit for BMW 550i, 750i, X5M, and X6M models equipped with the 4.4L V8 N63 and S63 engines. Crafted to meet OE/OEM standards, these rings are engineered to restore engine compression and improve overall efficiency, helping your BMW run at its peak performance. With precise dimensions of Φ89mm and a thickness of 1.5mm / 1.5mm / 2.0mm, this piston ring set is an ideal replacement for worn-out parts. The rings are compatible with a wrist pin diameter of 22mm, making them perfect for direct replacement without any modifications. Whether you're restoring your engine to its factory specs or performing a rebuild, this set ensures optimal sealing for reliable performance.