Abstract: A backup gap type over-voltage protector and thermal protector for a two element gas discharge tube. The gas discharge tube is mounted with its electrodes between opposing fingers of a clip of electrically conductive material. One of the clip fingers contacts the tube electrode that is to be grounded and the other finger is spaced from the other tube electrode that receives the voltage by a piece of thermally meltable, electrically insulating material having at least one hole that is located under the finger. Upon failure of the gas discharge tube, an over-voltage applied to the electrode jumps the gap formed by the hole in the insulating piece back to the clip finger and is conducted to ground. Upon thermal overload of the gas discharge tube, the insulating piece melts and brings the clip finger into contact with the tube electrode receiving the voltage and connects it and the voltage line to ground.