This piston and ring set is designed for N20B20A 2.0L turbocharged engines with a bore diameter of 84.00 mm, wrist pin diameter of 22 mm, and a compression ratio of 10:1.The set includes four pistons and matching piston rings with thicknesses of 1.2 mm, 1.5 mm, and 2.0 mm.It is compatible with standard cylinder bores and does not require overboring.Fits select models equipped with N20B20A, N26B20A, N20B20B, or N20B20D engine variants (1997 cc displacement), including: 125i (2010–2016), 220i (2012–2016), 228i (2012–2016), 320i (2012–2017), 328i (2011–2016), 320i GT (2012–2016), 328i GT (2012–2016), 420i (2013–2017), 428i (2013–2017), 520i (2010–2017), 528i (2011–2017), X1 20i (2009–2015), X1 28i (2009–2015), X3 20i (2011–2017), X3 28i (2011–2017), X4 20i (2013–2017), X4 28i (2013–2017), X5 28i (2013–2017), X5 40e (2013–2017), X6 28i (2014–2018), Z4 18i (2011–2016), Z4 20i (2011–2016), and Z4 28i (2011–2016).Replaces OEM part numbers 11258606459 and 87-434600-00.