This 4-piece piston ring set is designed for vehicles equipped with N20B20A or N26B20A 2.0L turbocharged engines.It is compatible with select 125i, 320i, 328i, 428i, 528i, X1, X3, and Z4 models from 2010 to 2018.Each piston features an 84mm bore and a 22mm pin diameter, engineered to support a 10:1 compression ratio.The set includes four complete piston and ring assemblies intended as direct replacements for worn or damaged components.Constructed with CR, Nural, and Goetze materials, these parts are built to meet performance specifications under normal operating conditions.Designed for precise fitment, this kit supports installation in applicable engine platforms and is intended for use by experienced DIY mechanics and professional technicians during engine rebuilds.