Check the listing for details. Universal Security Instruments BF-703BA 4-Inch Housing 70-CFM Bath Fan, 6 PACK. Color: Silver, Condition: New. Listed at 29.99 USD. The USI Electric BF-703BA Bath Exhaust Fan Contractor Pack with Rough-In Housing Kit is designed for the electrical professional and ideal for multiple installations with (6) housings and (6) duct collars included in the 12-piece set. Packaged for convenient and easy installation, this contractor pack will help avoid component loss and on-the-job storage issues during the installation of multiple fans. The BF-703BA housing and duct collar set is designed for use with 70 CFM bath fans and 3-inch ducts. Power leads are supplied with plug-in wire connectors, eliminating the need for wire nuts and saving time during installation. The quick connect plug is also corrosion resistant for a reliable and secure connection. Each housing and duct collar set comes preassembled for simple shipping and reduced installation time.