Nonmetallic cable boxes are used in branch circuit wiring to splice wires and accommodate wiring devices such as switches and receptacles. Vapor barrier boxes prevent unwanted penetration of exterior air and help contain the existing environment from escaping to the outside of the structure. Made from rugged polycarbonate material. Unique gasketing material that seals all openings to prevent air or vapor penetration. Front-mounted ground screw for convenience. Self-clamping, nonmetallic sheathed cable entry tabs. Designed to be used independently of vapor barrier hats.