1) Automobile air filtration felt 2) 20 years ... quality Features: 1) Non-woven filter paper for air filters has high strength, low shrink, heat resistance ... , good stabilityand air permeability,2) Its water proof, light-stopped, acid ... alkali resistant, mothproof and non-poisonous.3) Filtrated air includes the filtration & purification of noncorrosive gases such ...