4pcs Ø77mm PISTON RING N18 B16 A C STD 11257601181 11257601077 11257584117 for BWM 10-16 Countryman Paceman Set of four piston rings with a 77mm diameter designed for engines requiring the N18, B16 A C STD specification.Constructed from steel to support durability under engine operating conditions.The set includes rings sized to fit applications associated with part numbers 11257601181, 11257601077, and 11257584117.Engineered to maintain effective cylinder compression and sealing performance.Designed for use in models from 2010 to 2016 where compatibility aligns with the specified bore and OEM references.Installation requires standard 48mm bolts and is intended as a direct replacement without modifications.Meets specifications for fit and function. Compatibility Disclaimer: This is an aftermarket replacement part.Any brand names or model designations mentioned are used solely for the purpose of demonstrating compatibility.