- Fire-resistant, sound-proof and air-sealed
- Offset ribs on box give positive stop for the proper wall thickness
- Bright common nails or pierce-point screws fit securely in specially designed supports and are angled for easy installation
- Strip-resistant tapered and machine tapped device holes allow device screw to be started by hand
- Knockouts on fiberglass boxes are complete, reducing drafts and easily removed with wire for no-tool installation