Ultra-quiet wind turbine is designed to operate in a site with medium to high wind speed averages of 12 MPH and greater. Provides 100+ kWh per month (3.4 kWh per day) in a 12 MPH average wind. The Whisper 100 is one of the quietest wind turbines ever tested by the National Renewable Energy Labs. Ideal for cabins, 12V battery charging, remote power and backup power. U.S.A. Application: Cabins, Volts: 12-48V DC, Watts: 900 at 28 MPH, Blade Material: Polypro/carbon glass reinforced blades, Speed (MPH): 120, Material: Cast aluminum body, Rotor Size (ft.): 7, Overspeed/Overcrank Shutdown: Patented side furling Rated power: 900 Watts of power at 28 MPH wind speed Delivers 100 kWh per month (3.4 kWh per day) in a 12 MPH average wind Works in winds as low as 7.5 MPH Adjusts from 12-48V DC in minutes Includes controller to protect turbine and storage batteries Side-furling overspeed protection turns alternator & blades out of high winds without cutting power output Survival wind speed: 120 mph 7-ft. dia. rotor has polypro/carbon glass reinforced blades Alternator has cast aluminum body 4-bearing spindle for long life Bronze bushing and large-diameter furling pin for smooth furling action Uses 2.5in. Schedule 40 mount Installs in a few hours with no welding or concrete work required