NuTone QT300 High Capacity Fan, 300 CFM, White Grille Gracefully curved, rounded grilles - so slim they project a scant 5/8-Inch from the ceiling; Torsion springs hold grilles firmly in place Easy installation, includes pre-wired outlet boxes with plug-in receptacle; Suitable for use with solid state speed controls. Do not mount over bathtub or shower stall enclosure; Not intended for use in kitchens. Adjustable hanger brackets provide mounting between 16-Inch on-center joists; Mates to 3 1/4 x 10 inch rectangular exhaust ducting. Powerful, quiet ventilation (4.5 sones)for large baths, rec rooms, offices and conference rooms up to 375 square feet.