... Gram Weight,550 g/m2 Supply Activated Carbon Filter Material Features1.Using polyester, polyamide, nylon, etc. chemical synthetic fibers, ... into a conformation of the increase in density by nonwoven process, it has a property of high permeability ... fresh air, pre-filtering prior to medium-efficiency filter, as well as filtration of return air in ... : 20mmt×2m×20m Supply Activated Carbon Filter Material