Universal Security Instruments Bath Exhaust Fan with Custom-Designed Motor and Heat Bulb Attachment, 70 CFM, Model BF-704HB Bath Exhaust Fan combines high function with practical design to keep air moving and effectively pull out moisture Comes equipped with a 70-CFM 4.0-sones motor that is permanently lubricated so that it will not get louder over time Covers up to 85 square feet of living space and includes 4-inch duct adaptor with built-in damper Keyhole slots on the blower bracket simplifies installation so you can have a fully-functioning bath fan in no time Comes with a 3 year limited warranty