1.Self-produced motor with 100% real copper 2.Motor with long service and low noise 3.Three speeds ... :1) Four sizes: 500mm(20"), 600mm(24"),650mm(24"), 750mm(30")2)100% real copper motor with long service and low noise ... two blades or three blades for all 20",24",26",30"6) Steel base or plastic base7) Fan's color: can ... Series Stand Powerful Fan with Steel Base(20",24",26",30")