8pcs M157 Engine Pistons Rings Set made from aluminum designed for 5.5L engines with model number M157.This kit is compatible with vehicle models W166, C218, X218, W212, and S212.The set includes 8 piston rings and is engineered as a direct replacement for OEM part numbers 2780301317, 1570300117, 1570300517, and 1570300317.The components are built to proper fit and function.Designed for straightforward installation, this piston ring set supports efficient engine and under normal operating conditions. Compatibility Note: This is a third-party replacement component.Brand and model references are included solely to indicate fitment.