Marley 8100ESH Humidity Sensing Exhaust Fan ENERGY STAR RATED FAN FEATURES - Built in humidity sensor automatically detects humidity and turns on the fan. Manual override from wall switch. Plug in high efficiency motor with super quiet double inlet blower. High impact styrene grill with prism glass lens for even light distribution. Heavy duty galvanized housing and blower. Four adjustable mounting bars allows for placement anywhere between 16"oc and 24"oc ceiling joists. High density acoustical insulation to absorb noise. cULus listed IC for use in insulated ceilings. cULus listed for use over a tub or shower when wired on a UL listed GFCI protected circuit. 4" duct .29 amps 100 CFM 1.5 Sones Rough opening - 10-1/4" x 11-7/16" Grill size - 12-1/2" x 12-1/2" For baths up to 95 square feet and other rooms up to 125 square feet. PLEASE NOTE THE SHIPPING AND RETURN POLICIES NEAR THE BOTTOM OF OUR HOME PAGE.