1. 20 years reputation. 2. good quality. 3. for air filtration Features: 1. Nonwoven filter ... , low shrink ratio, heat resistance, good stability and air permeability. 2. It is waterproof, light-stopped, acid/alkali resistant, mothproof and ... purify kinds of noncorrosive gases, such as compressed air , oxygen,nitrogen, fuel gas etc, and can be used in serveral kinds of ...