Used for extending set back electrical boxes up to 1-1/2-inches, levels and supports wiring device Automatically levels and supports outlets, switches, GFCIs, and other standard devices Works with handy boxes and 4-inch square electrical boxes with plaster rings for single switches Manufactured from 94VO rated flame retardant plastic for safer installations, two hour fire rating Compliant with 2008 NEC Article 314.2 Used for extending set back electrical boxes up to 1-1/2-Inch, levels and supports wiring device Automatically levels and supports outlets, switches, GFCIs, and other standard devices