Master Flow? whole house fans are smart energy savers for any climate where cooling costs are a concern. They help beat the heat by forcing hot air out of the home while bringing in cooler outside air. Whole house fans are an important part of a complete home ventilation system.

Master Flow? whole house fans are smart energy savers for any climate where cooling costs are a concern. They help beat the heat by forcing hot air out of the home while bringing in cooler outside air. Whole house fans are an important part of a complete home ventilation system.

Master Flow Standard Timer, 115 V, 60 Hz Frequency, Vertical Mounting, Steel Housing Material, Dimensions: 2-1/2 in D, Suitable for: Fans, Includes: Plastic Knob, Wallplate

Master Flow Fan Shutter, Automatic, 42-1/2 in Length x 37-3/4 in Width Overall, 40-1/2 in Length x 35-7/8 in Width Opening, Aluminum, Enamel, White

Master Flow Fan Shutter, Automatic, 35-3/4 in Length x 30-1/4 in Width Overall, 33-3/4 in Length x 28-1/4 in Width Opening, Aluminum, Enamel, White