Delta BreezRadiance RAD80L 80 CFM Exhaust Bath Fan/CFL Light and Heater Quiet operation at 1.5 sones Built-in thermostat regulates temperature. Energy efficiency at 7.6 CFM/Watt Precision engineered with DC brushless motor for extended reliability, this fan will outlast many household appliances Galvanized steel construction resists corrosion Duct: Detachable 4-inch Plastic Duct Adapter