This heavy duty aluminum fan can be used as a blower or exhaust by simply reverse mounting. Compressed air is pushed through a nozzle at the end of each blade creating the fan to propel at speeds up to 11,000 CFM (20″ model) or 16,9000 CFM (24″ model) at 100 psig quickly and efficiently. Heavy duty ball bearings are permanently lubricated and sealed for the life of the fan. Added features include 3/4″ side mount inlet connector and fan is spark resistant. Easy to transport with recessed handles or it can be rolled.