7"x17" PP/PE needle Felt Filter Bags 1.Material:Needle felt PP,PE 2.Welding or Sewing ... Ring 4.Size, 7"x17" PP/PE needle Felt Filter Bags were made by PP,PE,Nylon,Nomex ... liquid purified with filter bag vesse together. 7"x17" PP/PE needle Felt Filter Bags1).Nominal micron filter bags (#1 ... ,#2,#3, ) 2).Absolute micron filter bags.(#1,#2,# ...