... many areas ,with high quality and good delivery. Metallic rasching rings are simple shaped, with the same size of height and ... diameter. Large size of the rings (100 MM above) use the whole build way of filling ... bed.Materials:stainless steels,carbon steels,aluminium,copper,bronze,304L,316L and aluminium permeated steels,improved polypropylene,improved Nylon6,Nylon66,reinforce ...