The Electrical Box Extender lends support to the contents of a wall box. This non-conductive extender helps prevent arcing by forming a barrier between the box and the metal screws on the device. This box extender has a 2-hour fire rating.Levels and supports wiring devices in an electrical boxHelps prevent arcing by forming a barrier between a metal box and metal side screws on the deviceHeavy-duty, non-conductive plastic constructionUL and CSA safety listingsComplies with 2008 NEC Article 314.20