The Nature Power 400 Watt Wind Turbine lets you harness wind energy 24/7. AC output at the turbine body ensures you keep the most possible power over long distances from generator to batteries. Application: 12V battery charging land or marine environment, Volts: 12, Watts: 400 @ 28 MPH, Blade Material: Carbon fiber composite, Speed (MPH): 6.7 startup; 5.6 charging; 110 max., Blade Diameter (in.): 47.2, Material: Cast aluminum body, Dimensions L x W x H (in.): 26 x 42 x 42, Rotor Size (ft.): 3.933, Overspeed/Overcrank Shutdown: 110 MPH Sturdy cast aluminum body is built to withstand wind speeds as high as 110 MPH Continually supplies power at a low 5.6 MPH 47.2in. dia. carbon fiber composite blades are engineered for low-noise operation Sleek black color. Easy assembly and low maintenance — a simple DIY task