... .Media ,ployester ,ployamide and synthetic fiber 3.Low resistance Supply Pre Filter Media Cotton Filter Features1.Using polyester, polyamide, nylon, etc ... as prevention and control of pollution, filtration of fresh air, pre-filtering prior to medium-efficiency filter, as well as filtration ... of dust catching450g/m2600g/m2520g/m2460g/m2400g/m2Production Picture Supply Pre Filter Media Cotton Filter