Project packs are ideal for contractors and builders who have yet to pick out the final product. With the housing for the fan sold separately from the grille and motor, contractors are able to continue with construction and not have to worry about damaging, losing or storing the product. Once all construction is complete, the purchase of a finish pack, 4 grilles and 4 motor/blower wheels, can be made to add the finishing touches to the room. 50 cu-ft/min, sufficient ventilation to remove odors and pollutants from your smaller powder room or bathroom 2.5 sones for quiet performance, enough sound to know your fan is on Double strength mounting flanges with keyhole slots Quiet polymeric damper prevents cold backdrafts Torsion spring grille mounting