7"x17" PP/PE needle Felt Filter Bags 1.Material:Needle felt PP,PE 2.Welding or Sewing 3.Plastic ... Steel Ring 4.Size, 7"x17" PP/PE needle Felt Filter Bags were made by PP,PE,Nylon,Nomex and Oil Absorbent ... 7"x17" PP/PE needle Felt Filter Bags1).Nominal micron filter bags (#1,#2,#3, ) 2).Absolute micron filter bags.(#1,#2,#3, ) ... (Silicon free)ST (Standard) 7"x17" PP/PE needle Felt Filter Bags