The Broan® ZB80M ULTRA GREEN™ 80 CFM Motion Sensing Exhaust Bath Fan, ENERGY STAR® delivers everything you wished for in a bath fan - premium ventilation to help reduce airborne pollutants, ease of installation, energy efficiency, consistent power, extremely quiet operation and multi-speed capability. ULTRASense™, Motion Sensing Technology, offers a hands-free solution for maximum convenience. The fan will increase to maximum speed from the lower, continuous setting when motion is detected - which is ideal for family members who forget to turn the fan on - and will stay on the max setting for the user-set 5-minutes to 60-minutes period after no motion is detected, before falling back to the continuous setting.