1. The outer frame is mainly made of aluminum and galvanized frames; There are thicknesses of 21mm, 25mm, and 46mm;
2. The filter material contains electrostatic fibers, which have a particularly good dust filtration effect, high dust capture rate and high breathability, and a long service life;
3. Each filter bag is fixed with metal strips to increase the strength of the filter and prevent the filter bag from breaking due to wind friction at high wind speeds.