Negative-pressure ventilation fan 1,industrial ccoling fan 2,CCC motor 3,CE Certification 4, low price TSBD-Negative-pressure air fanThe outline border adopt advanced automatic process, more accuracy, material galvanized sheet, good tensile and corrosion resistant. The 6-blade propeller is made of aluminium /magnesium alloy with light weight, high intensity and good toughness. The aluminum-case ...