WEXD series fan with forward swept blades, advanced low noise outer rotor or the inner rotor fan motor for direct drive, the design of square shell can be conveniently installed on the concrete wall, brick or steel profiled panels, square rain cover solid structure, beautiful appearance. The utility model has the advantages of low noise, large air flow, reliable operation, wide performance parameter range, simple installation, etc., and is widely used in the side wall wall ventilation of factories, mines, enterprises, workshops and civil and commercial construction projects. According to the requirements of conveying medium, it can be made into anticorrosive and explosion-proof type. WEXD (WEX) series fans are generally used for side wall wall ventilation, equipped with a 45 degree rain shield (or specially made to 60 degrees) and insect nets (at night to prevent insects from flying into the workshop with lights). It can be made into side wall fan according to requirement. The model is DWSP (WSP), equipped with 90 degree rainproof cover (wind, rain, dust) and insect net (at night, it can prevent insects from flying into workshop by lamplight). Attachment selection: gravity type check return valve (ensure that the workshop is kept out of the air when the fan is not open), when ordering.