VENTURI MOUNTED DIRECT DRIVE EXHAUST FANS 10"Diameter Fan Venturi mounted exhaust fans install on inside of wall. Venturi mount exhaust fans are designed for low-pressure exhausting and cooling applications. Fan is mounted to a steel venturi frame for easy installation to walls and shutters. 3 aluminum fan blades are enclosed in steel spiral wire guards for safety. 120V, single phase motor is totally enclosed and permanently lubricated for long life, UL listed. Exhaust fans feature pull chain operation. Includes junction box for direct wiring. Note: Rough-in hole size is 1/2" larger than fan blade size. Optional Wall Shutters available. Horsepower rating based upon maximum speed/load.