| 70 CFM 3.5 Sones | UL Listed for 60°C 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 250-watt BR40 size infrared bulbs (not included).