The 50 watt 4 blade vertical axis wind turbine is great for charging small batteries , emergency power , radio towers and charging small computer equipment. The unit boats 2 12 / 24 volt max. generators. Having a generator at the top and at the bottom of the unit offers high reliability and unsurpassed stability in high winds allow it to function in all wind speeds , thus increasing its value to charge batteries all the time. The unit boasts 4 abs plastic rotor blades black in color , 2 high strength steel supports connecting to the generators and 2 flanges with mounting holes to make mounting to a pole , tower or wall or post easy. the generators output ac voltage which is easily rectified for dc charging voltage.