HPM-Medium-efficiency Panel Filter ◆Trapping 65~95% of ≥1.0μm particles ◆Using special low-resistance and high-throughput non-woven fabrics as the filter material, with a high dust containing capacity ◆Frame can be made of galvanized steel sheet, stainless steel sheet, aluminum alloy or ABS plastic More info: http://www.hefilter.com/Air-filters/HPM-Medium-efficiency-Panel-Filter.shtml