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 Broan® LoProfile DC (LPDC) Fan is our solution for installations where conventional ventilation simply won't fit. Where multi-family applications require it, the LPDC fan is narrow enough to be installed in a wall between 2x4 studs. It also features selectable CFM, between 50, 80, and 100 CFM.