4″ Round drafttight Ceiling Fixture Electrical Outlet Box With 14.3″ to 22.5″ Hanger Bar. For use with non-metallic sheathed cable. Drafttight(TM) boxes are designed to meet the energy-efficiency requirements of modern homes. They feature a drywall flange covered with a foam gasket and additional gaskets over the cable entry points. These gaskets provide a vapor-tight seal, preventing the free flow of air through the box. This helps control heating costs in the winter and cooling costs in the summer.