Abstract: A metal halide arc discharge lamp includes a sealed outer envelope, an arc tube located within the envelope, a cylindrical shroud positioned around the arc tube, stops positioned at ends of the shroud to capture the shroud therebetween, and conduction wires which both provide electrical energy to the arc tube and mechanically support the arc tube and the shroud. The outside diameter of the shroud is maximized in relation to the inside diameter of the neck of the outer envelope such that the shroud can be inserted through the neck during manufacture of said lamp. In order to reduce electrolytic sodium loss, a conductor wire passing through the shroud in close proximity to the arc tube is surrounded by a ceramic sleeve to electrically insulate the conductor wire from the arc tube, and the stops are ceramic to electrically insulate the shroud from the conductor wires.