The Vortex PowerFan High Performance Duct Blowers are one of the best inline duct blowers on the market today. They come in 5 different sizes. The highest power motors combined with its aerodynamically designed shape make Vortex Powerfan the performance leader in its category. These high-performance inline blowers feature superior steel construction with powder-coated, baked paint and convenient sizes from 4 to 12 inches. They have a convenient "tape flange" that allows you to place the ducting on the blower and tape it in place easily! Balanced motors with permanently lubricated ball bearings ensure vibration-free operation. The Vortex blowers feature a 10-year warranty.