Medium Base Porcelain Socket Extenders are intended for use in an existing medium base socket where the light bulb socket needs to be extended to accept your desired light bulb or for aesthetic reasons. These E26 medium base socket extensions are rated for 660 watts and 250 volts. These socket extenders are made of porcelain. These socket adapters are NOT pulse rated. They are NOT for use in any fixure that utilizes and HID ballast. Please note: These adapters are CUL listed and are a convenience item. Under no circumstances is it recommended to use multiple socket adapters in a single socket application.