... features such as large flow Axail Fan with external rotor blower.It is widely applicable for the exhaust, ventilation, sunstroke prevention ... 250#, 300#4E 250#, 300#, 350#, 400#, 450#, 500#, 550#, 600#, 630#6E 350#, 400#, 450#, 500#, 550#, 600#, 630# Axial blower T630