70 CFM, 2 Bulb, Heater/Fan Combination Unit, 3.5 Sones, UL Listed For 60 Degrees Celsius Wiring, Retrofits, Type IC, Quiet, Highly Efficient Polymeric Blower Wheels, Polymeric Dampers Eliminate Metallic Clatter While Preventing Backdrafts, Polymeric 4" Round Duct Connectors With Tapered Sleeves Provide Easier, Positive Ducting, Adjustable Mounting Brackets With Keyhole Slots That Span Up To 24", Use 250W BR40 Size Infrared Bulbs, Not Included.