||This miniature neon glow lamp is of the lens end style designed for viewing through the top of the glass bulb. The electrodes are of pressed iron and have been sprayed on the back sides with a coating to prevent electron emission in this area - thus confining the discharge to just the front faces where the light generation is most useful.
Such lamps find applications on instrument panels as long-life alternatives to incandescent light sources. However for new installations, LED technology is almost exclusively employed today. The gas filling is essentially pure neon but incorporates a small percentage of argon to form a mixture for easy ignition on the mains electricity supply. A small ballast resistor is housed inside the 10mm diameter screw base so that the lamp can be operated direct from the mains electricity supply.
Note also the modified cap design on this lamp, termed type EX10s, which has a bulged profile to the external vitrite insulator portion. The purpose of this is to increase the tracking distance between the cap shell and base contact and make any electrical breakdown across the surface much less likely to occur at mains voltage.