1.The double inner yarn fan adopts customized special quick-opening hinge; 2.The opening position is sealed with three rubber strips toseparate the watertight chamber from the airtight chamber； 3.The outer frame adopts floor drain drainage structuredesign; 4.The inner fan is flush with the outer frame, and the indoorand outdoor frame fans are flush ; 5.The press line has optional color skipping line practice； 6.Outer frame, transfer frame and fan are designed by extruded aluminum gluing process ; 7.The group Angle flat steel sheet used is 304 stainlesssteellaminated steel sheet; 8.Fixed bit pressure line beveled edge design, more beautiful; 9.The small window screens of double inner openingWindows and micro ventilation Windows can be installedwith gold steel mesh or high permeability mesh; 10.The outdoor clearance width of the micro ventilationwindow is 110mm, which meets the safety requirements ofthe relevant regulations. 11.The whole frame adopts internal and external pressurestrip design to enhance air tightness.