Marley 8100A Ultra Quiet Ceiling Exhaust Fan Features - -Plug in high effiency mtor with super quiet double inlet blower. -New designer styled high impact styrene grill. -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. -4" duct with back draft damper reduces noisy air turbulence and comes pre-assemble to housing. -cULus listed IC for insulated ceilings. -cULul listed for use over a tub or shower shen wired on a UL listed GFCI protected circuit. -4" duct -Rough in opening: 10-1/4" x 11-7/16" -Grill size: 12-1/2" x 11-1/2" -.73 amps -100 CFM -1.5 Sones 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.