How do I fit the bungs into a Bottle or Ceramic base?

You can access a ‘screwdriver slot’ to turn to expand the bung to create a tight fit by removing the reducer that holds down the metal plate. Feed your 3 core braided flex down the bung and through the hole in your lamp then wire up the lampholder and attach it to the ½” threaded reducer on top of the bung.  Size 19-22mm fits a standard wine bottle.