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. F6A piston ring contains 3 piston rings which includs TOP ring,2nd ring and the oil ring.The material is steel.For the surface treatment,TOP ring is Chromium Plating and Oxidizing treatment,2nd is Phosphoric treatment, and the oil ring is Chromium Plating and Phosphoric treatment.The diameter is 65 mm, and the oversize is updated accordingly.