6 Set Pistons Rings Kit with Φ82mm bore and 11:1 compression ratio designed for engines with model number N52B25.This kit includes six sets of piston rings engineered to fit vehicles requiring specifications matching part numbers 11257612982 and 11257561848.The aluminum construction supports performance under standard operating conditions.Each ring set features a first ring thickness of 1.2mm, second ring of 1.5mm, and third ring of 2.0mm to help reduce wear and maintain consistent cylinder sealing.Designed for use in models from 2005 to 2011 including those with chassis codes E60, E90, and E92.engine compatibility before installation as this product is not intended for use in engines with expanded cylinder bores.