... iron, ductile iron rings;keystone ring, taper ring, drum ring;Chroming ring, spray molybdenum ring.Capacity:40 Millions Pcs/year.2 ... ring,keystone surface ring,cone surface ring,twist side ring,chromium plating ring,spray molybdenum ring,nitride ring,steel disc rng,as well as steel belt assembly oil ring ... requirements.Your inquiry will be welcomed. Auto parts(piston ring)for Cummins,engine parts