The gas discharge lamp has an arc-tube (10) with an integral glass bulb (12) containing a pair of electrodes (15) plus a UV filter bulb (20) enclosing the arc-tube and forming a single body with it. There is an insulating base (30) with a mounting (35) projecting forwards to hold the rear end of the combined arc-tube and filter bulb.The mounting also carries at the side a conductor (32) which is attached to the front electrode. The base is made from plastic resin and has a ceramic disc (33) at the front through which the tube-bulb unit is inserted. The disc is held on with a screw and an inorganic glue is used to fasten the tube-bulb unit.
