Hefei Sunber Autoparts Co., Ltd is a professional export company of auto parts which including piston rings,pistons,liners etc. We have our own plants for piston rings, piston,liners etc. Piston Ring BMW 1800 2000 518 520 ET Engine contains 3 pieces of piston rings which includs TOP ring,2nd ring and the oil ring.The diameter of it is 89 mm.The oversize of it is updated accordingly.The material of it is Ductile Cast Iron.