WhisperValue DC Fan with pre-installed condensation sensor helps control bathroom condensation to prevent mold and mildew. It is the lowest profile ENERGY STAR rated ventilation fan available. Ideal for residential construction (Single and Multi-Family) and Manufactured Homes. It features Panasonic?s revolutionary ECM motor with SmartFlow optimum CFM technology and incorporates a Pick-A-Flow speed selector switch to customize airflow (50-80-100 CFM). Precision spot ventilation fan ideal for residential construction (single and multifamily) and manufactured homes. Pick-A-Flow Speed Selector ? one fan you choose the CFM (50 80 or 100 CFM). Built-in condensation sensor to control bathroom moisture. Revolutionary ECM motor with SmartFlow technology for optimum CFM output. Low profile 3-3/8-in depth fits virtually anywhere including 2×4 construction; unique L-shaped bracket simplifies installation and provides strong support. Can be used to comply with ASHRAE 62. 2 LEED IAP California Title 24 CALGreen and WA Ventilation Code. Wall installation reduces cost by eliminating the need to incorporate a radiation damper when penetrating fire rated ceilings making it ideal for multi-family applications. 6-year on ECM motor; 3-year on parts.