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. The Flex™ Series housing and finish packs provide revolutionary innovations such as foldable mounting ears, a new damper, tighter housing to decrease air leakage, while the finish pack grilles complement any decor.