Xenon Gas Discharge
Bulb D2S

Xenon bulbs use an electric arc passed through Xenon gas, rather
than a filament, to produce light. This method requires minimal
electric current draw compared to filament lighting, and its output is comparable to daylight.

As the human eye has evolved to see in daylight, Xenon lighting causes less eye strain than other bulb types, making it a more convenient and safer night lighting option. Xenon bulbs increase reflections on road signs and markings.