Centrifugal Upblash Exhaust Fan, Model CUBE-300-20-G, Belt Driven, 208/230 Volt, 3 Phase - Windband is continually welded to the curb cap and drain trough for leakproof construction. Centrifugal wheel provides high-efficiency and minimal sound. One-piece aluminum windband with rolled bead provides extra rigidity. Cooling fins located on top of fan wheel draw outside air through a large breather tube directly into the motor compartment extending motor life. Wall or roof mountable.