... Piston Ring 1.Engine piston ring, auto piston ring 2.Different treatment:Phosphated, Nitrided etc. 3.ISO9002,QS9000,TS16949 Piston Ringpiston ring for Isuzu 4JB1:1.piston ring ... aslo do as per customer's request)2.piston ring surface treatment:polishing, plating, oxidation, phosphating ... long working life4.Our piston ring model as follows:CommodityPart NumberCummins piston ring6BT,6CT,NT855,NH220,NH250, ...