Ceiling Fan & Fixture Draft Tight, Saddle Box, With V-Clamps & Foam Gaskets. Dimensions: 4" round x 3-5/16"D, 16 cubic inch capacity. For use with non-metallic sheathed cable, Mounting with center screw. Polycarbonate constructions withstands temperature extremes, Meets energy efficiency requirements for new homes. Features a drywall flange with foam gaskets over cable entry points. Provides draft tight seal preventing flow of air thru box. 70 lb. fan/fixture, UL Listed.