Broan ZB80ML Ultra Series Multi-Speed Motion Sensing Ventilation Fan/Light, 80 CFM, 6" or 4" Duct Nullify Imported 80 CFM quickly reduces humidity to prevent or eliminate fogged mirrors and manage moisture in bathrooms up to 70 square feet Ultra sense m, motion sensing technology, offers a hands-free solution for maximum convenience Multi-speed operation handles demanding spot ventilation needs, but can also pull double-duty as a great continuous ventilation solution to meet today's stringent requirements Ultralucent Lighting technology provides 36 watt lights (two 18-watt bulbs included) delivering the brightness (measured in lumens) of models previously requiring 60 watts of cfl output Ultra silent with qstream sound technology results in operation at less than 0.3 sones  the quietest sound rating attainable -- for an environment that is so quiet, you'll likely forget the fan is on