Piston and rings set designed for use with W166 W221 W222 X166 GLS500 S500 E500 ML500 M278 4.6T 4.7T engines.Constructed from forged aluminum for and performance.Features a cylinder bore of Φ92.9mm (3.66 inches) and a pin bolt diameter of Φ24mm with a pin bolt length of 56mm.Includes 8 pieces per kit.Ring thickness is 1.2mm for the first ring, 1.5mm for the second ring, and 2.0mm for the third ring.Designed to fit specific engine configurations and intended to restore proper compression and reduce oil consumption.Engineered for under normal and driving conditions.Suitable for engine rebuilds where piston replacement is required. This is a compatible aftermarket part.References to brands or models do not imply OEM association.