The 360 cylindrical filter is designed for maximum intake. The triple-layer filter uses a primary filter, H13-grade High Efficiency Filter and activated carbon filter to remove dust, odors and other respirable particles. High-efficiency High performance 13420 ft³/h CADR. According to GB/T 6165-2008 test method of the performance of high efficiency particulate air High Efficiency Filter - efficiency and resistance, the filter medium can remove >99.97% of particles as small as 0.3 microns in charged condition.