Abstract: The present invention relates to an apparatus comprising a watt-hour meter adapter housing having a substantially cylindrical outline with a translucent window into its interior, and having visible therewithin one or more lights connected between respective input power phases and ground. The invention also relates to a transient voltage surge suppression (TVSS) apparatus containing a TVSS means including varistors in a housing fitting in a plug-and-jack manner between a watt-hour meter and its customary socket in a utility box or panel, improved on-line TVSS status indication means comprising a translucent window in the housing, and an indicator light connected to show the status and visible through the window to an outside observer.